diff --git a/.github/workflows/build-linux.yml b/.github/workflows/build-linux.yml
index e2d575c59..6b0272eb1 100644
--- a/.github/workflows/build-linux.yml
+++ b/.github/workflows/build-linux.yml
@@ -23,6 +23,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          submodules: true
       - name: Setup environment
         run: |
           sudo apt-get install -y libssl-dev
diff --git a/.github/workflows/build-windows.yml b/.github/workflows/build-windows.yml
index 310423b82..9839aa772 100644
--- a/.github/workflows/build-windows.yml
+++ b/.github/workflows/build-windows.yml
@@ -24,6 +24,8 @@ jobs:
         uses: microsoft/setup-msbuild@v2
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          submodules: true
       - name: Set up Python 3.10
         uses: actions/setup-python@v5
         with:
diff --git a/.github/workflows/super-linter.yml b/.github/workflows/super-linter.yml
index 19ef6a3f9..2ce018664 100644
--- a/.github/workflows/super-linter.yml
+++ b/.github/workflows/super-linter.yml
@@ -24,6 +24,7 @@ jobs:
           # Full git history is needed to get a proper list of changed files
           # within `super-linter`
           fetch-depth: 0
+          submodules: true
       - name: Super-linter
         uses: super-linter/super-linter@v7.3.0 # x-release-please-version
         env:
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..eab6041af
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "third_party/spdlog"]
+	path = third_party/spdlog
+	url = https://github.com/gabime/spdlog.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index caf3bf388..487e2857f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -98,6 +98,9 @@ endif()
 set(GLOO_INSTALL ON CACHE BOOL "")
 mark_as_advanced(GLOO_INSTALL)
 
+# Compile definitions for Gloo
+set(GLOO_COMPILE_DEFS)
+
 # Build shared or static libraries (override from parent project)
 if(BUILD_SHARED_LIBS)
   set(GLOO_STATIC_OR_SHARED SHARED CACHE STRING "")
diff --git a/README.md b/README.md
index d9d29ace7..63b6c5538 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,23 @@ Optional dependencies are:
 
 Please refer to [docs/](docs/) for detailed documentation.
 
+## Cloning
+
+Gloo makes use of [Git submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules)
+for third-party build-time dependencies. When cloning, ensure that you
+initialize and sync submodules:
+
+``` shell
+git clone --recurse-submodules https://github.com/pytorch/gloo.git # or use SSH remote
+```
+
+Or, if you already cloned without submodules, run the following in the existing
+local repository:
+
+``` shell
+git submodule update --init --recursive
+```
+
 ## Building
 
 You can build Gloo using CMake.
diff --git a/cmake/Dependencies.cmake b/cmake/Dependencies.cmake
index 63873fc64..7ca837a8d 100644
--- a/cmake/Dependencies.cmake
+++ b/cmake/Dependencies.cmake
@@ -2,6 +2,9 @@ set(gloo_DEPENDENCY_LIBS "")
 set(gloo_cuda_DEPENDENCY_LIBS "")
 set(gloo_hip_DEPENDENCY_LIBS "")
 
+# Dependency libraries for all Gloo targets (e.g. tests, benchmarks, etc.)
+set(gloo_ALL_TARGETS_DEPENDENCY_LIBS "")
+
 # Configure path to modules (for find_package)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${PROJECT_SOURCE_DIR}/cmake/Modules/")
 
@@ -104,7 +107,7 @@ if(USE_MPI)
     message(STATUS "MPI libraries: " ${MPI_CXX_LIBRARIES})
     include_directories(SYSTEM ${MPI_CXX_INCLUDE_PATH})
     list(APPEND gloo_DEPENDENCY_LIBS ${MPI_CXX_LIBRARIES})
-    add_definitions(-DGLOO_USE_MPI=1)
+    list(APPEND GLOO_COMPILE_DEFS "GLOO_USE_MPI=1")
   else()
     message(WARNING "Not compiling with MPI support. Suppress this warning with -DUSE_MPI=OFF.")
     set(USE_MPI OFF)
@@ -199,3 +202,19 @@ if(BUILD_TEST)
     target_link_libraries(gtest INTERFACE ${GTEST_LIBRARIES})
   endif()
 endif()
+
+set(SPDLOG_BUILD_SHARED OFF CACHE BOOL "" FORCE)
+set(SPDLOG_BUILD_PIC ON CACHE BOOL "" FORCE)
+set(SPDLOG_FMT_EXTERNAL OFF CACHE BOOL "" FORCE)
+
+set(_save_BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS})
+set(BUILD_SHARED_LIBS OFF)
+add_subdirectory(third_party/spdlog EXCLUDE_FROM_ALL)
+set(BUILD_SHARED_LIBS ${_save_BUILD_SHARED_LIBS})
+
+if(GLOO_STATIC_OR_SHARED STREQUAL "STATIC")
+  list(APPEND gloo_ALL_TARGETS_DEPENDENCY_LIBS $<BUILD_INTERFACE:spdlog::spdlog_header_only>)
+else()
+  list(APPEND gloo_ALL_TARGETS_DEPENDENCY_LIBS spdlog::spdlog)
+  list(APPEND GLOO_COMPILE_DEFS SPDLOG_COMPILED_LIB)
+endif()
diff --git a/docs/errors.md b/docs/errors.md
index 93f1279b7..94248d584 100644
--- a/docs/errors.md
+++ b/docs/errors.md
@@ -18,4 +18,4 @@ extend `::gloo::Exception`.
 ## Assertions
 Gloo asserts unexpected errors and logical invariants instead of expecting
 callers to handle them. `GLOO_ENFORCE` macros are defined in
-[`logging.h`](../gloo/common/logging.h)
+[`enforce.h`](../gloo/common/enforce.h)
diff --git a/gloo/CMakeLists.txt b/gloo/CMakeLists.txt
index 186fe1288..11dd34b79 100644
--- a/gloo/CMakeLists.txt
+++ b/gloo/CMakeLists.txt
@@ -147,10 +147,12 @@ if(USE_CUDA)
     cuda_add_library(gloo_cuda ${GLOO_CUDA_SRCS} ${GLOO_STATIC_OR_SHARED})
   endif()
   target_link_libraries(gloo_cuda gloo ${gloo_cuda_DEPENDENCY_LIBS})
+  set_property(TARGET gloo_cuda APPEND PROPERTY LINK_LIBRARIES ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 endif()
 if(USE_ROCM)
   gloo_hip_add_library(gloo_hip ${GLOO_HIP_SRCS})
   target_link_libraries(gloo_hip gloo)
+  set_property(TARGET gloo_hip APPEND PROPERTY LINK_LIBRARIES ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 endif()
 if(USE_LIBUV)
   target_link_libraries(gloo PRIVATE uv_a)
@@ -165,7 +167,8 @@ elseif(USE_TCP_OPENSSL_LOAD)
   target_link_libraries(gloo PRIVATE dl)
 endif()
 
-target_link_libraries(gloo PRIVATE ${gloo_DEPENDENCY_LIBS})
+target_link_libraries(gloo PRIVATE ${gloo_DEPENDENCY_LIBS} ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
+target_compile_definitions(gloo PRIVATE ${GLOO_COMPILE_DEFS})
 
 # Add Interface include directories that are relocatable.
 target_include_directories(gloo INTERFACE $<INSTALL_INTERFACE:include>)
diff --git a/gloo/algorithm.cc b/gloo/algorithm.cc
index 9488ff59d..bc2d06fe1 100644
--- a/gloo/algorithm.cc
+++ b/gloo/algorithm.cc
@@ -8,7 +8,7 @@
 
 #include "gloo/algorithm.h"
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 namespace gloo {
 
diff --git a/gloo/allgather.cc b/gloo/allgather.cc
index 8ab4e6f4f..b45a0215f 100644
--- a/gloo/allgather.cc
+++ b/gloo/allgather.cc
@@ -11,7 +11,7 @@
 #include <array>
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/allgatherv.cc b/gloo/allgatherv.cc
index 72fc3988e..50db2a143 100644
--- a/gloo/allgatherv.cc
+++ b/gloo/allgatherv.cc
@@ -11,7 +11,7 @@
 #include <cstring>
 #include <numeric>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/allreduce.cc b/gloo/allreduce.cc
index 080f7f302..00da4dff7 100644
--- a/gloo/allreduce.cc
+++ b/gloo/allreduce.cc
@@ -12,7 +12,7 @@
 #include <array>
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/math.h"
 #include "gloo/types.h"
 
diff --git a/gloo/allreduce_bcube.cc b/gloo/allreduce_bcube.cc
new file mode 100644
index 000000000..2aed4606f
--- /dev/null
+++ b/gloo/allreduce_bcube.cc
@@ -0,0 +1,74 @@
+#include "gloo/allreduce_bcube.h"
+
+#include <string_view>
+
+#include "gloo/common/log.h"
+
+namespace gloo {
+
+template <typename T>
+void AllreduceBcube<T>::printElems(T* p, int count, int start) {
+  /* Early return if log level is not high enough, to prevent expensive code
+   * running. */
+  if (!spdlog::should_log(spdlog::level::trace))
+    return;
+
+  const std::size_t alignedStart = (start / wordsPerLine) * wordsPerLine;
+  fmt::memory_buffer line{};
+
+  /* Logs/flushes the line buffer - starting a new line */
+  auto printLine = [&]() {
+    if (!line.size())
+      return;
+    std::string_view sv{line.data(), line.size()};
+    GLOO_TRACE("{}", sv);
+    line.clear();
+  };
+
+  for (std::size_t x = alignedStart; x < start + count; ++x) {
+    if (x % wordsPerLine == 0) {
+      if (x != alignedStart)
+        printLine();
+      fmt::format_to(
+          std::back_inserter(line), "{} {:05}: ", fmt::ptr(&p[x]), x);
+    } else if (x % wordsPerSection == 0) {
+      fmt::format_to(std::back_inserter(line), "- ");
+    }
+
+    if (x < start)
+      fmt::format_to(std::back_inserter(line), "..... ");
+    else
+      fmt::format_to(std::back_inserter(line), "{:05} ", p[x]);
+  }
+  printLine();
+}
+
+template <typename T>
+void AllreduceBcube<T>::printStageBuffer(const std::string& msg) {
+  if (printCheck(myRank_)) {
+    GLOO_TRACE("rank ({}) {}:", myRank_, msg);
+    printElems(&ptrs_[0][0], totalNumElems_);
+  }
+}
+
+template <typename T>
+void AllreduceBcube<T>::printStepBuffer(
+    const std::string& stage,
+    int step,
+    int srcRank,
+    int destRank,
+    T* p,
+    int count,
+    int start) {
+  if (printCheck(myRank_)) {
+    GLOO_TRACE(
+        "{}: step ({}) srcRank ({}) -> destRank ({})",
+        stage,
+        step,
+        srcRank,
+        destRank);
+    printElems(p, count, start);
+  }
+}
+
+} // namespace gloo
diff --git a/gloo/allreduce_bcube.h b/gloo/allreduce_bcube.h
index c91fa130d..ff094efa8 100644
--- a/gloo/allreduce_bcube.h
+++ b/gloo/allreduce_bcube.h
@@ -13,15 +13,12 @@
 #include <string.h>
 #include <algorithm>
 #include <cstring>
-#include <iomanip>
-#include <iostream>
 #include <memory>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include "gloo/algorithm.h"
-#include "gloo/common/error.h"
 #include "gloo/context.h"
 
 /**
@@ -537,48 +534,18 @@ class AllreduceBcube : public Algorithm {
   static bool printCheck(int /*rank*/) {
     return false;
   }
-  /**
-   * Prints a break given the offset of an element about to be printed
-   * @param p Pointer to the elements
-   * @param x The current offset to the pointer to words
-   */
-  static void printBreak(T* p, int x) {
-    if (0 == x % wordsPerLine) {
-      std::cout << std::endl
-                << &p[x] << " " << std::setfill('0') << std::setw(5) << x
-                << ": ";
-    } else if (0 == x % wordsPerSection) {
-      std::cout << "- ";
-    }
-  }
   /**
    * Pretty prints a list of elements
    * @param p Pointer to the elements
    * @param count The number of elements to be printed
    * @param start The offset from which to print
    */
-  static void printElems(T* p, int count, int start = 0) {
-    auto alignedStart = (start / wordsPerLine) * wordsPerLine;
-    for (int x = alignedStart; x < start + count; ++x) {
-      printBreak(p, x);
-      if (x < start) {
-        std::cout << "..... ";
-      } else {
-        std::cout << std::setfill('0') << std::setw(5) << p[x] << " ";
-      }
-    }
-  }
+  static void printElems(T* p, int count, int start);
   /**
    * Prints contents in the ptrs array at a particular stage
    * @param msg Custom message to be printed
    */
-  void printStageBuffer(const std::string& msg) {
-    if (printCheck(myRank_)) {
-      std::cout << "rank (" << myRank_ << ") " << msg << ": ";
-      printElems(&ptrs_[0][0], totalNumElems_);
-      std::cout << std::endl;
-    }
-  }
+  void printStageBuffer(const std::string& msg);
 
   /**
    * Prints specified buffer during a step
@@ -596,14 +563,7 @@ class AllreduceBcube : public Algorithm {
       int destRank,
       T* p,
       int count,
-      int start = 0) {
-    if (printCheck(myRank_)) {
-      std::cout << stage << ": step (" << step << ") " << "srcRank (" << srcRank
-                << ") -> " << "destRank (" << destRank << "): ";
-      printElems(p, count, start);
-      std::cout << std::endl;
-    }
-  }
+      int start = 0);
   /**
    * Get all the peers of node with specified rank
    * @param rank Rank of the node for which peers are needed
diff --git a/gloo/alltoall.cc b/gloo/alltoall.cc
index aa7db9a87..2ce5d5754 100644
--- a/gloo/alltoall.cc
+++ b/gloo/alltoall.cc
@@ -10,7 +10,7 @@
 
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/alltoall.h b/gloo/alltoall.h
index c588f9b2c..448d2c209 100644
--- a/gloo/alltoall.h
+++ b/gloo/alltoall.h
@@ -8,7 +8,7 @@
 
 #pragma once
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/context.h"
 #include "gloo/transport/unbound_buffer.h"
 
diff --git a/gloo/alltoallv.cc b/gloo/alltoallv.cc
index 7a51f9527..612ad8a06 100644
--- a/gloo/alltoallv.cc
+++ b/gloo/alltoallv.cc
@@ -11,7 +11,7 @@
 #include <cstring>
 #include <numeric>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/alltoallv.h b/gloo/alltoallv.h
index b0bb21e10..b7761d89a 100644
--- a/gloo/alltoallv.h
+++ b/gloo/alltoallv.h
@@ -8,7 +8,7 @@
 
 #pragma once
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/context.h"
 #include "gloo/transport/unbound_buffer.h"
 
diff --git a/gloo/benchmark/CMakeLists.txt b/gloo/benchmark/CMakeLists.txt
index 74da2c04b..2c8069131 100644
--- a/gloo/benchmark/CMakeLists.txt
+++ b/gloo/benchmark/CMakeLists.txt
@@ -5,7 +5,7 @@ set(GLOO_BENCHMARK_SRCS
   )
 
 add_executable(benchmark ${GLOO_BENCHMARK_SRCS})
-target_link_libraries(benchmark gloo)
+target_link_libraries(benchmark gloo ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 
 if(GLOO_INSTALL)
   install(TARGETS benchmark DESTINATION ${CMAKE_INSTALL_PREFIX}/bin)
diff --git a/gloo/benchmark/cuda_main.cc b/gloo/benchmark/cuda_main.cc
index 387338f6e..7736f2b97 100644
--- a/gloo/benchmark/cuda_main.cc
+++ b/gloo/benchmark/cuda_main.cc
@@ -11,7 +11,7 @@
 
 #include "gloo/benchmark/benchmark.h"
 #include "gloo/benchmark/runner.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda_allreduce_bcube.h"
 #include "gloo/cuda_allreduce_halving_doubling.h"
 #include "gloo/cuda_allreduce_halving_doubling_pipelined.h"
diff --git a/gloo/benchmark/main.cc b/gloo/benchmark/main.cc
index 2e4678006..d7e19f060 100644
--- a/gloo/benchmark/main.cc
+++ b/gloo/benchmark/main.cc
@@ -26,7 +26,7 @@
 #include "gloo/broadcast_one_to_all.h"
 #include "gloo/common/aligned_allocator.h"
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/context.h"
 #include "gloo/pairwise_exchange.h"
 #include "gloo/reduce.h"
diff --git a/gloo/benchmark/runner.cc b/gloo/benchmark/runner.cc
index f73dade2b..ed3cbaab9 100644
--- a/gloo/benchmark/runner.cc
+++ b/gloo/benchmark/runner.cc
@@ -15,7 +15,7 @@
 #include "gloo/barrier_all_to_one.h"
 #include "gloo/broadcast_one_to_all.h"
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/rendezvous/context.h"
 #include "gloo/rendezvous/file_store.h"
 #include "gloo/rendezvous/prefix_store.h"
diff --git a/gloo/broadcast.cc b/gloo/broadcast.cc
index 14f0fc2b4..311d16a00 100644
--- a/gloo/broadcast.cc
+++ b/gloo/broadcast.cc
@@ -11,7 +11,7 @@
 #include <algorithm>
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/math.h"
 #include "gloo/types.h"
 
diff --git a/gloo/broadcast_one_to_all.h b/gloo/broadcast_one_to_all.h
index e599e102f..e8910bb76 100644
--- a/gloo/broadcast_one_to_all.h
+++ b/gloo/broadcast_one_to_all.h
@@ -13,7 +13,7 @@
 
 #include "gloo/algorithm.h"
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 namespace gloo {
 
diff --git a/gloo/common/CMakeLists.txt b/gloo/common/CMakeLists.txt
index a8d474498..ebf0fb23d 100644
--- a/gloo/common/CMakeLists.txt
+++ b/gloo/common/CMakeLists.txt
@@ -1,13 +1,13 @@
 set(GLOO_COMMON_SRCS
-  "${CMAKE_CURRENT_SOURCE_DIR}/logging.cc"
+  "${CMAKE_CURRENT_SOURCE_DIR}/enforce.cc"
   "${CMAKE_CURRENT_SOURCE_DIR}/utils.cc"
   )
 
 set(GLOO_COMMON_HDRS
   "${CMAKE_CURRENT_SOURCE_DIR}/aligned_allocator.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/common.h"
+  "${CMAKE_CURRENT_SOURCE_DIR}/enforce.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/error.h"
-  "${CMAKE_CURRENT_SOURCE_DIR}/logging.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/store.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/string.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/utils.h"
diff --git a/gloo/common/logging.cc b/gloo/common/enforce.cc
similarity index 50%
rename from gloo/common/logging.cc
rename to gloo/common/enforce.cc
index 91b02ea18..879a33c2e 100644
--- a/gloo/common/logging.cc
+++ b/gloo/common/enforce.cc
@@ -6,42 +6,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
-#include <algorithm>
-#include <cstring>
 #include <numeric>
 
 namespace gloo {
 
-// Initialize log level from environment variable, and return static value at
-// each inquiry.
-LogLevel logLevel() {
-  // Global log level. Initialized once.
-  static LogLevel log_level = LogLevel::UNSET;
-  if (log_level != LogLevel::UNSET) {
-    return log_level;
-  }
-
-  const char* level = getenv("GLOO_LOG_LEVEL");
-  // Defaults to WARN.
-  if (level == nullptr) {
-    log_level = LogLevel::WARN;
-    return log_level;
-  }
-
-  if (std::strcmp(level, "DEBUG") == 0) {
-    log_level = LogLevel::DEBUG;
-  } else if (std::strcmp(level, "INFO") == 0) {
-    log_level = LogLevel::INFO;
-  } else if (std::strcmp(level, "WARN") == 0) {
-    log_level = LogLevel::WARN;
-  } else {
-    log_level = LogLevel::ERROR;
-  }
-  return log_level;
-}
-
 EnforceNotMet::EnforceNotMet(
     const char* file,
     const int line,
diff --git a/gloo/common/logging.h b/gloo/common/enforce.h
similarity index 81%
rename from gloo/common/logging.h
rename to gloo/common/enforce.h
index c5e7c1da9..d940a3fc1 100644
--- a/gloo/common/logging.h
+++ b/gloo/common/enforce.h
@@ -10,58 +10,12 @@
 
 #include <climits>
 #include <exception>
-#include <functional>
-#include <iostream>
-#include <limits>
 #include <vector>
 
-#include "gloo/common/error.h"
 #include "gloo/common/string.h"
 
 namespace gloo {
 
-enum LogLevel {
-  ERROR,
-  WARN,
-  INFO,
-  DEBUG,
-  UNSET,
-};
-
-LogLevel logLevel();
-
-#define GLOO_LOG_MSG(level, ...)   \
-  std::cerr << ::gloo::MakeString( \
-      "[", __FILE__, ":", __LINE__, "] ", level, " ", __VA_ARGS__, "\n")
-
-#define GLOO_ERROR(...)                   \
-  do {                                    \
-    if (logLevel() >= LogLevel::ERROR) {  \
-      GLOO_LOG_MSG("ERROR", __VA_ARGS__); \
-    }                                     \
-  } while (0)
-
-#define GLOO_WARN(...)                   \
-  do {                                   \
-    if (logLevel() >= LogLevel::WARN) {  \
-      GLOO_LOG_MSG("WARN", __VA_ARGS__); \
-    }                                    \
-  } while (0)
-
-#define GLOO_INFO(...)                   \
-  do {                                   \
-    if (logLevel() >= LogLevel::INFO) {  \
-      GLOO_LOG_MSG("INFO", __VA_ARGS__); \
-    }                                    \
-  } while (0)
-
-#define GLOO_DEBUG(...)                   \
-  do {                                    \
-    if (logLevel() >= LogLevel::DEBUG) {  \
-      GLOO_LOG_MSG("DEBUG", __VA_ARGS__); \
-    }                                     \
-  } while (0)
-
 class EnforceNotMet : public std::exception {
  public:
   EnforceNotMet(
diff --git a/gloo/common/linux.cc b/gloo/common/linux.cc
index 9b45fc314..784e5e8f9 100644
--- a/gloo/common/linux.cc
+++ b/gloo/common/linux.cc
@@ -28,7 +28,7 @@
 #include <map>
 #include <mutex>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 #ifndef SPEED_UNKNOWN
 /* SPEED_UNKOWN is sometimes undefined, c.f.
diff --git a/gloo/common/log.h b/gloo/common/log.h
new file mode 100644
index 000000000..cde3eacde
--- /dev/null
+++ b/gloo/common/log.h
@@ -0,0 +1,72 @@
+#pragma once
+
+/**
+ * @file log.h
+ * @brief This header is intended to be internal only, so as not to make spdlog
+ * a dependency of gloo library consumers. For this reason, it should not be
+ * included by public headers.
+ */
+
+/* The compile-time log level is set to the most sensitive (TRACE), to ensure no
+ * logging statements are removed at build time. This allows logging to be fully
+ * controllable at runtime, even to the TRACE level. */
+#define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_TRACE
+
+#include <spdlog/cfg/env.h>
+#include <spdlog/spdlog.h>
+
+/* ranges.h provides formatter for containers, e.g. std::vector */
+#include <spdlog/fmt/ranges.h>
+
+namespace gloo::log {
+
+inline void init() {
+  /* Default to WARN log level */
+  spdlog::set_level(spdlog::level::warn);
+  /* Override log level if the environment variable is set. */
+  spdlog::cfg::load_env_levels("GLOO_LOG_LEVEL");
+
+  /* Set custom format. This is similiar to PyTorch's format. Equivalent to:
+   * [{short-log-level}{month-num}{day-of-month} {hour}:{min}:{sec}.{microsec}
+   * {threadid} {source_file}:{line_no}] {MESSAGE} */
+  spdlog::set_pattern("[%L%m%d %H:%M:%S.%f %t %s:%#] %v");
+}
+
+inline std::once_flag onceFlag;
+
+inline void ensureInit() {
+  std::call_once(onceFlag, [] { init(); });
+}
+
+} // namespace gloo::log
+
+#define GLOO_TRACE(...)        \
+  do {                         \
+    ::gloo::log::ensureInit(); \
+    SPDLOG_TRACE(__VA_ARGS__); \
+  } while (0)
+#define GLOO_DEBUG(...)        \
+  do {                         \
+    ::gloo::log::ensureInit(); \
+    SPDLOG_DEBUG(__VA_ARGS__); \
+  } while (0)
+#define GLOO_INFO(...)         \
+  do {                         \
+    ::gloo::log::ensureInit(); \
+    SPDLOG_INFO(__VA_ARGS__);  \
+  } while (0)
+#define GLOO_WARN(...)         \
+  do {                         \
+    ::gloo::log::ensureInit(); \
+    SPDLOG_WARN(__VA_ARGS__);  \
+  } while (0)
+#define GLOO_ERROR(...)        \
+  do {                         \
+    ::gloo::log::ensureInit(); \
+    SPDLOG_ERROR(__VA_ARGS__); \
+  } while (0)
+#define GLOO_CRITICAL(...)        \
+  do {                            \
+    ::gloo::log::ensureInit();    \
+    SPDLOG_CRITICAL(__VA_ARGS__); \
+  } while (0)
diff --git a/gloo/common/win.cc b/gloo/common/win.cc
index 5dfb80e28..bbce93c6c 100644
--- a/gloo/common/win.cc
+++ b/gloo/common/win.cc
@@ -7,7 +7,7 @@
  */
 
 #include "gloo/common/win.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 #include <mutex>
 
diff --git a/gloo/context.cc b/gloo/context.cc
index fd9b83c7b..a919163ac 100644
--- a/gloo/context.cc
+++ b/gloo/context.cc
@@ -8,8 +8,8 @@
 
 #include "gloo/context.h"
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/transport/device.h"
 #include "gloo/transport/unbound_buffer.h"
 
diff --git a/gloo/cuda.h b/gloo/cuda.h
index ccb196a24..39049ba76 100644
--- a/gloo/cuda.h
+++ b/gloo/cuda.h
@@ -16,7 +16,7 @@
 #include <cuda_runtime.h>
 
 #include "gloo/algorithm.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/config.h"
 
 // Check that configuration header was properly generated
diff --git a/gloo/cuda_allreduce_bcube.cc b/gloo/cuda_allreduce_bcube.cc
index 065862f95..8374c8fb4 100644
--- a/gloo/cuda_allreduce_bcube.cc
+++ b/gloo/cuda_allreduce_bcube.cc
@@ -8,11 +8,13 @@
 
 #include "gloo/cuda_allreduce_bcube.h"
 
+#include "gloo/common/log.h"
 #include "gloo/cuda_collectives_device.h"
 #include "gloo/cuda_collectives_host.h"
 #include "gloo/cuda_private.h"
 
 #include <sstream>
+#include <string_view>
 #ifndef _WIN32
 #include <unistd.h>
 #endif
@@ -226,35 +228,48 @@ bool CudaAllreduceBcube<T, W>::printCheck(int /* rank */) {
   return false;
 }
 
-template <typename T, typename W>
-void CudaAllreduceBcube<T, W>::printBreak(T* p, int x) {
-  if (0 == x % wordsPerLine) {
-    std::cout << std::endl
-              << &p[x] << " " << std::setfill('0') << std::setw(5) << x << ": ";
-  } else if (0 == x % wordsPerSection) {
-    std::cout << "- ";
-  }
-}
-
 template <typename T, typename W>
 void CudaAllreduceBcube<T, W>::printElems(T* p, int count, int start) {
-  auto alignedStart = (start / wordsPerLine) * wordsPerLine;
-  for (int x = alignedStart; x < start + count; ++x) {
-    printBreak(p, x);
-    if (x < start) {
-      std::cout << "..... ";
-    } else {
-      std::cout << std::setfill('0') << std::setw(5) << p[x] << " ";
+  /* Early return if log level is not high enough, to prevent expensive code
+   * running. */
+  if (!spdlog::should_log(spdlog::level::trace))
+    return;
+
+  const std::size_t alignedStart = (start / wordsPerLine) * wordsPerLine;
+  fmt::memory_buffer line{};
+
+  /* Logs/flushes the line buffer - starting a new line */
+  auto printLine = [&]() {
+    if (!line.size())
+      return;
+    std::string_view sv{line.data(), line.size()};
+    GLOO_TRACE("{}", sv);
+    line.clear();
+  };
+
+  for (std::size_t x = alignedStart; x < start + count; ++x) {
+    if (x % wordsPerLine == 0) {
+      if (x != alignedStart)
+        printLine();
+      fmt::format_to(
+          std::back_inserter(line), "{} {:05}: ", fmt::ptr(&p[x]), x);
+    } else if (x % wordsPerSection == 0) {
+      fmt::format_to(std::back_inserter(line), "- ");
     }
+
+    if (x < start)
+      fmt::format_to(std::back_inserter(line), "..... ");
+    else
+      fmt::format_to(std::back_inserter(line), "{:05} ", p[x]);
   }
+  printLine();
 }
 
 template <typename T, typename W>
 void CudaAllreduceBcube<T, W>::printStageBuffer(const std::string& msg) {
   if (printCheck(myRank_)) {
-    std::cout << "rank (" << myRank_ << ") " << msg << ": ";
+    GLOO_TRACE("rank ({}) {}:", myRank_, msg);
     printElems(&scratch_[0], totalNumElems_);
-    std::cout << std::endl;
   }
 }
 
@@ -268,10 +283,13 @@ void CudaAllreduceBcube<T, W>::printStepBuffer(
     int count,
     int start) {
   if (printCheck(myRank_)) {
-    std::cout << stage << ": step (" << step << ") " << "srcRank (" << srcRank
-              << ") -> " << "destRank (" << destRank << "): ";
+    GLOO_TRACE(
+        "{}: step ({}) srcRank ({}) -> destRank ({}):",
+        stage,
+        step,
+        srcRank,
+        destRank);
     printElems(p, count, start);
-    std::cout << std::endl;
   }
 }
 
diff --git a/gloo/cuda_allreduce_local.cc b/gloo/cuda_allreduce_local.cc
index 9c31e5e46..52c78f054 100644
--- a/gloo/cuda_allreduce_local.cc
+++ b/gloo/cuda_allreduce_local.cc
@@ -8,7 +8,7 @@
 
 #include "gloo/cuda_allreduce_local.h"
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda_collectives_device.h"
 #include "gloo/cuda_private.h"
 
diff --git a/gloo/cuda_collectives_device.h b/gloo/cuda_collectives_device.h
index c2c6a81d1..2cace96a8 100644
--- a/gloo/cuda_collectives_device.h
+++ b/gloo/cuda_collectives_device.h
@@ -12,7 +12,7 @@
 #include <cmath>
 
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/config.h"
 #include "gloo/cuda.h"
 #include "gloo/cuda_private.h"
diff --git a/gloo/cuda_collectives_host.h b/gloo/cuda_collectives_host.h
index 32eb6d3ef..2f9579162 100644
--- a/gloo/cuda_collectives_host.h
+++ b/gloo/cuda_collectives_host.h
@@ -9,7 +9,7 @@
 #pragma once
 
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda.h"
 
 namespace gloo {
diff --git a/gloo/cuda_collectives_native.h b/gloo/cuda_collectives_native.h
index e6c45c401..07b21384d 100644
--- a/gloo/cuda_collectives_native.h
+++ b/gloo/cuda_collectives_native.h
@@ -13,7 +13,7 @@
 #include <random>
 
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda.h"
 #include "gloo/cuda_private.h"
 
diff --git a/gloo/cuda_collectives_nccl.h b/gloo/cuda_collectives_nccl.h
index acc64a6b0..ffec2463c 100644
--- a/gloo/cuda_collectives_nccl.h
+++ b/gloo/cuda_collectives_nccl.h
@@ -9,7 +9,7 @@
 #pragma once
 
 #include "gloo/common/common.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/nccl/nccl.h"
 
 namespace gloo {
diff --git a/gloo/cuda_private.h b/gloo/cuda_private.h
index 355fedd06..9fc353980 100644
--- a/gloo/cuda_private.h
+++ b/gloo/cuda_private.h
@@ -16,7 +16,7 @@
 #ifdef __linux__
 #include "gloo/common/linux.h"
 #endif
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda.h"
 #include "gloo/transport/device.h"
 
diff --git a/gloo/examples/CMakeLists.txt b/gloo/examples/CMakeLists.txt
index b5f87e85c..a5fba49cf 100644
--- a/gloo/examples/CMakeLists.txt
+++ b/gloo/examples/CMakeLists.txt
@@ -1,8 +1,8 @@
 if(MSVC)
     add_executable(example_reduce example_reduce.cc)
-    target_link_libraries(example_reduce gloo)
+    target_link_libraries(example_reduce gloo ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
     add_executable(example_allreduce example_allreduce.cc)
-    target_link_libraries(example_allreduce gloo)
+    target_link_libraries(example_allreduce gloo ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 
     if(USE_LIBUV)
         add_custom_command(TARGET example_reduce POST_BUILD
@@ -12,7 +12,7 @@ if(MSVC)
     endif()
 else()
     add_executable(example1 example1.cc)
-    target_link_libraries(example1 gloo)
+    target_link_libraries(example1 gloo ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
     add_executable(looks_like_mpi looks_like_mpi.cc)
-    target_link_libraries(looks_like_mpi gloo)
+    target_link_libraries(looks_like_mpi gloo ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 endif()
diff --git a/gloo/gather.cc b/gloo/gather.cc
index cab5ffadc..c86ed29ad 100644
--- a/gloo/gather.cc
+++ b/gloo/gather.cc
@@ -10,7 +10,7 @@
 
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/gatherv.cc b/gloo/gatherv.cc
index 306f6e45f..c0deb61f3 100644
--- a/gloo/gatherv.cc
+++ b/gloo/gatherv.cc
@@ -11,7 +11,7 @@
 #include <cstring>
 #include <numeric>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/mpi/context.cc b/gloo/mpi/context.cc
index e8c287960..245a1af56 100644
--- a/gloo/mpi/context.cc
+++ b/gloo/mpi/context.cc
@@ -12,8 +12,8 @@
 #include <cstring>
 #include <mutex>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/transport/address.h"
 
 namespace gloo {
diff --git a/gloo/nccl/nccl.h b/gloo/nccl/nccl.h
index 35746e350..0e6d5356f 100644
--- a/gloo/nccl/nccl.h
+++ b/gloo/nccl/nccl.h
@@ -13,7 +13,7 @@
 #include <string>
 #include <vector>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/cuda.h"
 #include "gloo/types.h"
 
diff --git a/gloo/pairwise_exchange.h b/gloo/pairwise_exchange.h
index f0da7552f..03550865f 100644
--- a/gloo/pairwise_exchange.h
+++ b/gloo/pairwise_exchange.h
@@ -11,7 +11,7 @@
 #include <math.h>
 
 #include "gloo/algorithm.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/context.h"
 
 namespace gloo {
diff --git a/gloo/reduce.cc b/gloo/reduce.cc
index 4ace5607d..41d7db00c 100644
--- a/gloo/reduce.cc
+++ b/gloo/reduce.cc
@@ -12,7 +12,7 @@
 #include <array>
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/math.h"
 #include "gloo/types.h"
 
diff --git a/gloo/rendezvous/context.cc b/gloo/rendezvous/context.cc
index f71739d3a..7db0a17cd 100644
--- a/gloo/rendezvous/context.cc
+++ b/gloo/rendezvous/context.cc
@@ -10,7 +10,7 @@
 
 #include <memory>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/rendezvous/store.h"
 #include "gloo/transport/address.h"
 
diff --git a/gloo/rendezvous/file_store.cc b/gloo/rendezvous/file_store.cc
index 1202e80f0..12a1b34e9 100644
--- a/gloo/rendezvous/file_store.cc
+++ b/gloo/rendezvous/file_store.cc
@@ -26,8 +26,8 @@
 #include <io.h>
 #endif
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 
 namespace gloo {
 namespace rendezvous {
diff --git a/gloo/rendezvous/hash_store.cc b/gloo/rendezvous/hash_store.cc
index 34c0951f7..984c46d0d 100644
--- a/gloo/rendezvous/hash_store.cc
+++ b/gloo/rendezvous/hash_store.cc
@@ -8,8 +8,8 @@
 
 #include "gloo/rendezvous/hash_store.h"
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 
 namespace gloo {
 namespace rendezvous {
diff --git a/gloo/rendezvous/redis_store.cc b/gloo/rendezvous/redis_store.cc
index f4d91fb2a..503162178 100644
--- a/gloo/rendezvous/redis_store.cc
+++ b/gloo/rendezvous/redis_store.cc
@@ -10,8 +10,8 @@
 
 #include <thread>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/common/string.h"
 
 namespace gloo {
diff --git a/gloo/rendezvous/store.h b/gloo/rendezvous/store.h
index e2569d0ef..b32e5f72c 100644
--- a/gloo/rendezvous/store.h
+++ b/gloo/rendezvous/store.h
@@ -12,8 +12,8 @@
 #include <string>
 #include <vector>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/common/store.h"
 
 // can be used by upstream users to know whether this is available or not.
diff --git a/gloo/scatter.cc b/gloo/scatter.cc
index c1810ca47..e7317a62e 100644
--- a/gloo/scatter.cc
+++ b/gloo/scatter.cc
@@ -11,7 +11,7 @@
 #include <algorithm>
 #include <cstring>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/types.h"
 
 namespace gloo {
diff --git a/gloo/test/CMakeLists.txt b/gloo/test/CMakeLists.txt
index d16af64e9..e97738575 100644
--- a/gloo/test/CMakeLists.txt
+++ b/gloo/test/CMakeLists.txt
@@ -17,7 +17,7 @@ set(GLOO_TEST_SRCS
   "${CMAKE_CURRENT_SOURCE_DIR}/remote_key_test.cc"
   "${CMAKE_CURRENT_SOURCE_DIR}/send_recv_test.cc"
   )
-set(GLOO_TEST_LIBRARIES)
+set(GLOO_TEST_LIBRARIES ${gloo_ALL_TARGETS_DEPENDENCY_LIBS})
 
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
   list(APPEND GLOO_TEST_SRCS
@@ -64,7 +64,7 @@ if(USE_CUDA)
     else()
       cuda_add_executable(gloo_test_cuda ${GLOO_TEST_CUDA_SRCS})
     endif()
-    target_link_libraries(gloo_test_cuda gloo_cuda gtest OpenSSL::SSL OpenSSL::Crypto ${GLOO_CUDA_LIBRARIES})
+    target_link_libraries(gloo_test_cuda gloo_cuda gtest ${GLOO_TEST_LIBRARIES} ${GLOO_CUDA_LIBRARIES})
   endif()
 endif()
 
@@ -79,5 +79,5 @@ if(USE_ROCM)
     )
 
   gloo_hip_add_executable(gloo_test_hip ${GLOO_TEST_HIP_SRCS})
-  target_link_libraries(gloo_test_hip gloo_hip gtest OpenSSL::SSL OpenSSL::Crypto)
+  target_link_libraries(gloo_test_hip gloo_hip gtest ${GLOO_TEST_LIBRARIES})
 endif()
diff --git a/gloo/test/base_test.cc b/gloo/test/base_test.cc
index ccccfa3bb..b5cf44bc8 100644
--- a/gloo/test/base_test.cc
+++ b/gloo/test/base_test.cc
@@ -7,6 +7,7 @@
  */
 
 #include "gloo/test/base_test.h"
+#include "gloo/common/log.h"
 #include "gloo/test/openssl_utils.h"
 
 namespace gloo {
@@ -81,7 +82,7 @@ std::shared_ptr<::gloo::transport::Device> createDevice(Transport transport) {
     try {
       return ::gloo::transport::ibverbs::CreateDevice(attr);
     } catch (const InvalidOperationException& e) {
-      GLOO_INFO("IBVERBS not available: ", e.what());
+      GLOO_INFO("IBVERBS not available: {}", e.what());
     }
   }
 #endif
diff --git a/gloo/test/multiproc_test.h b/gloo/test/multiproc_test.h
index e639fc3e7..0e4193052 100644
--- a/gloo/test/multiproc_test.h
+++ b/gloo/test/multiproc_test.h
@@ -15,7 +15,7 @@
 #include <chrono>
 #include <string>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/rendezvous/context.h"
 #include "gloo/rendezvous/file_store.h"
 #include "gloo/test/base_test.h"
diff --git a/gloo/test/openssl_utils.cc b/gloo/test/openssl_utils.cc
index 485f78e25..8eb9f0ba9 100644
--- a/gloo/test/openssl_utils.cc
+++ b/gloo/test/openssl_utils.cc
@@ -5,7 +5,7 @@
 #include "gloo/test/openssl_utils.h"
 #if GLOO_HAVE_TRANSPORT_TCP_TLS
 
-#include <gloo/common/logging.h>
+#include <gloo/common/enforce.h>
 #include <cstdlib>
 
 namespace gloo {
diff --git a/gloo/transport/buffer.h b/gloo/transport/buffer.h
index 382061a87..8431d37b6 100644
--- a/gloo/transport/buffer.h
+++ b/gloo/transport/buffer.h
@@ -16,13 +16,9 @@ namespace transport {
 class Buffer {
  public:
   explicit Buffer(int slot, void* ptr, size_t size)
-      : slot_(slot), ptr_(ptr), size_(size), debug_(false) {}
+      : slot_(slot), ptr_(ptr), size_(size) {}
   virtual ~Buffer() = 0;
 
-  virtual void setDebug(bool debug) {
-    debug_ = debug;
-  }
-
   virtual void send(size_t offset, size_t length, size_t roffset = 0) = 0;
 
   // Send entire buffer by default
@@ -37,7 +33,6 @@ class Buffer {
   int slot_;
   void* ptr_;
   size_t size_;
-  bool debug_;
 };
 
 } // namespace transport
diff --git a/gloo/transport/ibverbs/address.cc b/gloo/transport/ibverbs/address.cc
index 7f1b9d0c5..050a813e7 100644
--- a/gloo/transport/ibverbs/address.cc
+++ b/gloo/transport/ibverbs/address.cc
@@ -12,7 +12,7 @@
 
 #include <array>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 namespace gloo {
 namespace transport {
diff --git a/gloo/transport/ibverbs/buffer.cc b/gloo/transport/ibverbs/buffer.cc
index bb39e8b04..64836641b 100644
--- a/gloo/transport/ibverbs/buffer.cc
+++ b/gloo/transport/ibverbs/buffer.cc
@@ -6,16 +6,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/ibverbs/buffer.h"
-
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
-
 #include <iostream>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/log.h"
+#include "gloo/transport/ibverbs/buffer.h"
 
 namespace gloo {
 namespace transport {
@@ -63,7 +62,8 @@ Buffer::~Buffer() {
     std::lock_guard<std::mutex> lock(m_);
     if (sendPending_ > 0) {
       GLOO_WARN(
-          "Destructing buffer with pending sends, sendPending_=", sendPending_);
+          "Destructing buffer with pending sends, sendPending_={}",
+          sendPending_.load());
     }
 
     ibv_dereg_mr(mr_);
@@ -189,11 +189,7 @@ void Buffer::send(size_t offset, size_t length, size_t roffset) {
 
     checkErrorState();
 
-    if (debug_) {
-      std::cout << "[" << getpid() << "] ";
-      std::cout << "send " << length << " bytes";
-      std::cout << std::endl;
-    }
+    GLOO_TRACE("send {} bytes", length);
 
     // Increment number of sends in flight
     sendPending_++;
@@ -208,19 +204,11 @@ void Buffer::handleCompletion(int rank, struct ibv_wc* wc) {
   std::unique_lock<std::mutex> lock(m_);
 
   if (wc->opcode & IBV_WC_RECV) {
-    if (debug_) {
-      std::cout << "[" << getpid() << "] ";
-      std::cout << "recv " << wc->byte_len << " bytes";
-      std::cout << std::endl;
-    }
+    GLOO_TRACE("recv {} bytes", wc->byte_len);
     recvCompletions_++;
     recvCv_.notify_one();
   } else if (wc->opcode == IBV_WC_RDMA_WRITE) {
-    if (debug_) {
-      std::cout << "[" << getpid() << "] ";
-      std::cout << "send complete";
-      std::cout << std::endl;
-    }
+    GLOO_TRACE("send complete");
     sendCompletions_++;
     sendPending_--;
     sendCv_.notify_one();
diff --git a/gloo/transport/ibverbs/device.cc b/gloo/transport/ibverbs/device.cc
index ef0d5a123..6146e7f86 100644
--- a/gloo/transport/ibverbs/device.cc
+++ b/gloo/transport/ibverbs/device.cc
@@ -6,18 +6,17 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/ibverbs/device.h"
-
 #include <fcntl.h>
 #include <poll.h>
-#include <string.h>
-
 #include <algorithm>
+#include <cstring>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
 #include "gloo/common/linux.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/log.h"
 #include "gloo/transport/ibverbs/context.h"
+#include "gloo/transport/ibverbs/device.h"
 #include "gloo/transport/ibverbs/pair.h"
 
 namespace gloo {
@@ -85,9 +84,8 @@ std::shared_ptr<::gloo::transport::Device> CreateDevice(
     std::vector<std::string> names;
     for (auto i = 0; i < devices.size(); i++) {
       GLOO_DEBUG(
-          "found candidate device ",
+          "found candidate device {} dev={}",
           devices[i]->name,
-          " dev=",
           devices[i]->dev_name);
       names.push_back(devices[i]->name);
     }
@@ -96,11 +94,9 @@ std::shared_ptr<::gloo::transport::Device> CreateDevice(
   }
 
   GLOO_INFO(
-      "Using ibverbs device=",
+      "Using ibverbs device={} port={} index={}",
       attr.name,
-      " port=",
       attr.port,
-      " index=",
       attr.index);
 
   // Look for specified device name
@@ -227,7 +223,7 @@ void Device::loop() {
       Pair* pair = static_cast<Pair*>(cqContext);
       pair->handleCompletionEvent();
     } catch (const std::exception& ex) {
-      GLOO_ERROR("Exception while handling completion event: ", ex.what());
+      GLOO_ERROR("Exception while handling completion event: {}", ex.what());
       throw;
     }
   }
diff --git a/gloo/transport/ibverbs/memory_region.cc b/gloo/transport/ibverbs/memory_region.cc
index 83320dd2d..702bcb9f8 100644
--- a/gloo/transport/ibverbs/memory_region.cc
+++ b/gloo/transport/ibverbs/memory_region.cc
@@ -10,7 +10,7 @@
 
 #include <string.h>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 namespace gloo {
 namespace transport {
diff --git a/gloo/transport/ibverbs/pair.cc b/gloo/transport/ibverbs/pair.cc
index d3a0410bb..0ede8ae96 100644
--- a/gloo/transport/ibverbs/pair.cc
+++ b/gloo/transport/ibverbs/pair.cc
@@ -6,16 +6,16 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/ibverbs/pair.h"
-#include "gloo/transport/ibverbs/buffer.h"
-#include "gloo/transport/ibverbs/unbound_buffer.h"
-
-#include <stdlib.h>
-#include <string.h>
+#include <cstdlib>
+#include <cstring>
 
 #include "gloo/common/common.h"
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/log.h"
+#include "gloo/transport/ibverbs/buffer.h"
+#include "gloo/transport/ibverbs/pair.h"
+#include "gloo/transport/ibverbs/unbound_buffer.h"
 
 namespace gloo {
 namespace transport {
@@ -231,7 +231,7 @@ void Pair::sendMemoryRegion(struct ibv_mr* src, int slot) {
   wr.imm_data = slot;
 
   GLOO_DEBUG(
-      "sendMemoryRegion slot=", slot, " addr=", src->addr, " lkey=", src->lkey);
+      "sendMemoryRegion slot={} addr={} lkey={}", slot, src->addr, src->lkey);
 
   // The work request is serialized and sent to the driver so it
   // doesn't need to be valid after the ibv_post_send call.
@@ -331,7 +331,7 @@ void Pair::send(
     size_t offset,
     size_t nbytes) {
   std::unique_lock<std::mutex> lock(m_);
-  GLOO_DEBUG("send tag=", slot, " offset=", offset, " nbytes=", nbytes);
+  GLOO_DEBUG("send tag={} offset={} nbytes={}", slot, offset, nbytes);
 
   GLOO_ENFORCE(!sync_, "Cannot send in sync mode");
 
@@ -364,15 +364,11 @@ void Pair::send(
         wr.wr.rdma.rkey = peer.rkey;
 
         GLOO_DEBUG(
-            "send UnboundBuffer async slot=",
+            "send UnboundBuffer async slot={} peer_addr={} remote_addr={:#x} "
+            "rkey={}",
             wr.wr_id,
-            " peer_addr=",
             peer.addr,
-            " remote_addr=",
-            std::hex,
             wr.wr.rdma.remote_addr,
-            std::dec,
-            " rkey=",
             wr.wr.rdma.rkey);
 
         struct ibv_send_wr* bad_wr;
@@ -391,7 +387,7 @@ void Pair::recv(
     size_t nbytes) {
   std::unique_lock<std::mutex> lock(m_);
 
-  GLOO_DEBUG("recv tag=", tag, " offset=", offset, " nbytes=", nbytes);
+  GLOO_DEBUG("recv tag={} offset={} nbytes={}", tag, offset, nbytes);
 
   GLOO_ENFORCE(!sync_, "Cannot recv in sync mode");
 
@@ -445,19 +441,13 @@ void Pair::put(
   wr.wr.rdma.rkey = key->rkey_;
 
   GLOO_DEBUG(
+      "{}->{}: put UnboundBuffer async slot={} peer_addr={} "
+      "remote_addr={:#x} rkey={}",
       self_.str(),
-      "->",
       peer_.str(),
-      ": ",
-      "put UnboundBuffer async slot=",
       wr.wr_id,
-      " peer_addr=",
       key->addr_,
-      " remote_addr=",
-      std::hex,
       wr.wr.rdma.remote_addr,
-      std::dec,
-      " rkey=",
       wr.wr.rdma.rkey);
 
   struct ibv_send_wr* bad_wr;
@@ -507,19 +497,13 @@ void Pair::get(
   wr.wr.rdma.rkey = key->rkey_;
 
   GLOO_DEBUG(
+      "{}->{}: get UnboundBuffer async slot={} peer_addr={} "
+      "remote_addr={:#x} rkey={}",
       self_.str(),
-      "->",
       peer_.str(),
-      ": ",
-      "get UnboundBuffer async slot=",
       wr.wr_id,
-      " peer_addr=",
       key->addr_,
-      " remote_addr=",
-      std::hex,
       wr.wr.rdma.remote_addr,
-      std::dec,
-      " rkey=",
       wr.wr.rdma.rkey);
 
   struct ibv_send_wr* bad_wr;
@@ -585,11 +569,9 @@ void Pair::pollCompletions() {
         handleCompletion(&wc[i]);
       } catch (const std::exception& ex) {
         GLOO_ERROR(
+            "{}->{}: Exception in handleCompletion: {}",
             self_.str(),
-            "->",
             peer_.str(),
-            ": ",
-            "Exception in handleCompletion: ",
             ex.what());
         throw;
       }
@@ -604,13 +586,11 @@ void Pair::pollCompletions() {
 
 void Pair::handleCompletion(struct ibv_wc* wc) {
   GLOO_DEBUG(
+      "{}->{}: handleCompletion id={} opcode={}",
       self_.str(),
-      "->",
       peer_.str(),
-      ": handleCompletion id=",
       wc->wr_id,
-      " opcode=",
-      wc->opcode);
+      fmt::underlying(wc->opcode));
 
   if (wc->opcode == IBV_WC_RECV_RDMA_WITH_IMM) {
     // Incoming RDMA write completed.
@@ -657,12 +637,10 @@ void Pair::handleCompletion(struct ibv_wc* wc) {
     }
   } else if (wc->opcode == IBV_WC_RECV) {
     GLOO_DEBUG(
+        "{}->{}: handleCompletion id={} opcode=IBV_WC_RECV slot={}",
         self_.str(),
-        "->",
         peer_.str(),
-        ": handleCompletion id=",
         wc->wr_id,
-        " opcode=IBV_WC_RECV slot=",
         wc->imm_data);
     // Memory region recv completed.
     //
@@ -706,12 +684,10 @@ void Pair::handleCompletion(struct ibv_wc* wc) {
     // Memory region send completed.
 
     GLOO_DEBUG(
+        "{}->{}: handleCompletion id={} opcode=IBV_WC_SEND",
         self_.str(),
-        "->",
         peer_.str(),
-        ": handleCompletion id=",
-        wc->wr_id,
-        " opcode=IBV_WC_SEND");
+        wc->wr_id);
 
     auto slot = wc->wr_id;
     GLOO_ENFORCE_EQ(
@@ -750,15 +726,10 @@ void Pair::send(Buffer* buffer, size_t offset, size_t length, size_t roffset) {
         wr.wr.rdma.rkey = peer.rkey;
 
         GLOO_DEBUG(
-            "send Buffer async slot=",
+            "send Buffer async slot={} peer_addr={} remote_addr={:#x} rkey={}",
             wr.wr_id,
-            " peer_addr=",
             peer.addr,
-            " remote_addr=",
-            std::hex,
             wr.wr.rdma.remote_addr,
-            std::dec,
-            " rkey=",
             wr.wr.rdma.rkey);
 
         struct ibv_send_wr* bad_wr;
@@ -781,7 +752,7 @@ void Pair::send(Buffer* buffer, size_t offset, size_t length, size_t roffset) {
 
 void Pair::signalIoFailure(const std::string& msg) {
   std::lock_guard<std::mutex> lock(m_);
-  GLOO_ERROR(msg);
+  GLOO_ERROR("{}", msg);
   auto ex = ::gloo::IoException(msg);
   if (ex_ == nullptr) {
     // If we haven't seen an error yet, store the exception to throw on future
diff --git a/gloo/transport/ibverbs/unbound_buffer.cc b/gloo/transport/ibverbs/unbound_buffer.cc
index 971535d7c..e3a4fd022 100644
--- a/gloo/transport/ibverbs/unbound_buffer.cc
+++ b/gloo/transport/ibverbs/unbound_buffer.cc
@@ -6,13 +6,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/ibverbs/unbound_buffer.h"
-
 #include <cstring>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/log.h"
 #include "gloo/transport/ibverbs/context.h"
+#include "gloo/transport/ibverbs/unbound_buffer.h"
 
 namespace gloo {
 namespace transport {
@@ -106,9 +106,8 @@ void UnboundBuffer::handleCompletion(int rank, struct ibv_wc* wc) {
     sendCv_.notify_one();
 
     GLOO_DEBUG(
-        "send complete sendPending=",
+        "send complete sendPending={} sendCompletions={}",
         sendPending_,
-        " sendCompletions=",
         sendCompletions_);
   } else {
     GLOO_ENFORCE(false, "Unexpected completion (opcode: ", wc->opcode, ")");
diff --git a/gloo/transport/pair.h b/gloo/transport/pair.h
index 42ef7cd69..93eabf783 100644
--- a/gloo/transport/pair.h
+++ b/gloo/transport/pair.h
@@ -10,7 +10,7 @@
 
 #include <memory>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/transport/address.h"
 #include "gloo/transport/buffer.h"
 #include "gloo/transport/unbound_buffer.h"
diff --git a/gloo/transport/tcp/CMakeLists.txt b/gloo/transport/tcp/CMakeLists.txt
index acaf906b7..62691dd55 100644
--- a/gloo/transport/tcp/CMakeLists.txt
+++ b/gloo/transport/tcp/CMakeLists.txt
@@ -5,7 +5,6 @@ else()
       "${CMAKE_CURRENT_SOURCE_DIR}/address.cc"
       "${CMAKE_CURRENT_SOURCE_DIR}/buffer.cc"
       "${CMAKE_CURRENT_SOURCE_DIR}/context.cc"
-      "${CMAKE_CURRENT_SOURCE_DIR}/debug_logger.cc"
       "${CMAKE_CURRENT_SOURCE_DIR}/device.cc"
       "${CMAKE_CURRENT_SOURCE_DIR}/error.cc"
       "${CMAKE_CURRENT_SOURCE_DIR}/helpers.cc"
@@ -21,7 +20,6 @@ else()
       "${CMAKE_CURRENT_SOURCE_DIR}/buffer.h"
       "${CMAKE_CURRENT_SOURCE_DIR}/context.h"
       "${CMAKE_CURRENT_SOURCE_DIR}/debug_data.h"
-      "${CMAKE_CURRENT_SOURCE_DIR}/debug_logger.h"
       "${CMAKE_CURRENT_SOURCE_DIR}/device.h"
       "${CMAKE_CURRENT_SOURCE_DIR}/error.h"
       "${CMAKE_CURRENT_SOURCE_DIR}/helpers.h"
diff --git a/gloo/transport/tcp/address.cc b/gloo/transport/tcp/address.cc
index e37f7b493..93c540d11 100644
--- a/gloo/transport/tcp/address.cc
+++ b/gloo/transport/tcp/address.cc
@@ -13,7 +13,7 @@
 #include <memory>
 #include <mutex>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 
 namespace gloo {
 namespace transport {
diff --git a/gloo/transport/tcp/buffer.cc b/gloo/transport/tcp/buffer.cc
index 54a5e1119..1bee06e30 100644
--- a/gloo/transport/tcp/buffer.cc
+++ b/gloo/transport/tcp/buffer.cc
@@ -6,16 +6,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/tcp/buffer.h"
-
 #include <string.h>
 #include <sys/syscall.h>
 #include <unistd.h>
-
 #include <iostream>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
+#include "gloo/common/log.h"
+#include "gloo/transport/tcp/buffer.h"
 
 namespace gloo {
 namespace transport {
@@ -126,12 +125,7 @@ void Buffer::send(size_t offset, size_t length, size_t roffset) {
   // to support this.
   GLOO_ENFORCE_LE(offset + length, size_);
 
-  if (debug_) {
-    std::cout << "[" << getpid() << ": " << syscall(SYS_gettid) << "] ";
-    std::cout << "send " << length << " bytes";
-    std::cout << " to " << pair_->peer().str();
-    std::cout << std::endl;
-  }
+  GLOO_TRACE("send {} bytes to {}", length, pair_->peer().str());
 
   op.preamble.nbytes = sizeof(op.preamble) + length;
   op.preamble.opcode = Op::SEND_BUFFER;
diff --git a/gloo/transport/tcp/context.cc b/gloo/transport/tcp/context.cc
index 023178741..28e527cd5 100644
--- a/gloo/transport/tcp/context.cc
+++ b/gloo/transport/tcp/context.cc
@@ -6,16 +6,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "gloo/transport/tcp/context.h"
-
 #include <algorithm>
 #include <cstdint>
 #include <cstring>
-#include <iostream>
 #include <string>
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
+#include "gloo/common/log.h"
 #include "gloo/common/utils.h"
+#include "gloo/transport/tcp/context.h"
 #include "gloo/transport/tcp/device.h"
 #include "gloo/transport/tcp/pair.h"
 #include "gloo/transport/tcp/unbound_buffer.h"
@@ -241,17 +240,14 @@ std::vector<int> Context::getUnConnectedPeerRanks() const {
 void Context::printConnectivityInfo() const {
   int numConnectedPeers = getConnectedPeerRanks().size();
   GLOO_INFO(
-      "Rank ",
+      "Rank {} is connected to {}. Expected number of connected peers is: {}",
       rank,
-      " is connected to ",
       numConnectedPeers,
-      ". Expected number of connected peers is: ",
       size - 1);
 
   if (numConnectedPeers != size - 1) {
     std::vector<int> unConnectedPeers = getUnConnectedPeerRanks();
-    auto peerStrCat = ::gloo::MakeString<int>(unConnectedPeers, /*delim=*/", ");
-    GLOO_INFO("Rank ", rank, " is NOT connected to: [", peerStrCat, "]");
+    GLOO_INFO("Rank {} is NOT connected to: {}", rank, unConnectedPeers);
   }
 }
 
diff --git a/gloo/transport/tcp/debug_data.h b/gloo/transport/tcp/debug_data.h
index 71863067e..699836b98 100644
--- a/gloo/transport/tcp/debug_data.h
+++ b/gloo/transport/tcp/debug_data.h
@@ -1,11 +1,10 @@
 // (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
+#pragma once
 
+#include <spdlog/fmt/fmt.h>
 #include <string>
-#pragma once
 
-namespace gloo {
-namespace transport {
-namespace tcp {
+namespace gloo::transport::tcp {
 
 struct ConnectDebugData {
   const int retryCount;
@@ -18,6 +17,23 @@ struct ConnectDebugData {
   const std::string local;
 };
 
-} // namespace tcp
-} // namespace transport
-} // namespace gloo
+} // namespace gloo::transport::tcp
+
+template <>
+struct fmt::formatter<gloo::transport::tcp::ConnectDebugData>
+    : fmt::formatter<std::string> {
+  auto format(gloo::transport::tcp::ConnectDebugData& data, format_context& ctx)
+      const -> decltype(ctx.out()) {
+    return fmt::format_to(
+        ctx.out(),
+        "willRetry={}, retry={}, retryLimit={}, rank={}, size={}, local={}, remote={}, error={}",
+        data.willRetry,
+        data.retryCount,
+        data.retryLimit,
+        data.glooRank,
+        data.glooSize,
+        data.local,
+        data.remote,
+        data.error);
+  }
+};
diff --git a/gloo/transport/tcp/debug_logger.cc b/gloo/transport/tcp/debug_logger.cc
deleted file mode 100644
index b55209616..000000000
--- a/gloo/transport/tcp/debug_logger.cc
+++ /dev/null
@@ -1,30 +0,0 @@
-#include <gloo/common/logging.h>
-#include <gloo/transport/tcp/debug_logger.h>
-
-namespace gloo {
-namespace transport {
-namespace tcp {
-
-void DebugLogger::log(const ConnectDebugData& data) {
-  GLOO_ERROR(
-      "failed to connect, willRetry=",
-      data.willRetry,
-      ", retry=",
-      data.retryCount,
-      ", retryLimit=",
-      data.retryLimit,
-      ", rank=",
-      data.glooRank,
-      ", size=",
-      data.glooSize,
-      ", local=",
-      data.local,
-      ", remote=",
-      data.remote,
-      ", error=",
-      data.error);
-}
-
-} // namespace tcp
-} // namespace transport
-} // namespace gloo
diff --git a/gloo/transport/tcp/debug_logger.h b/gloo/transport/tcp/debug_logger.h
deleted file mode 100644
index e58f9c6a1..000000000
--- a/gloo/transport/tcp/debug_logger.h
+++ /dev/null
@@ -1,20 +0,0 @@
-// (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
-
-#pragma once
-
-#include <gloo/transport/tcp/debug_data.h>
-
-namespace gloo {
-namespace transport {
-namespace tcp {
-
-class DebugLogger {
- public:
-  static void log(const ConnectDebugData& data);
-
- private:
-};
-
-} // namespace tcp
-} // namespace transport
-} // namespace gloo
diff --git a/gloo/transport/tcp/device.cc b/gloo/transport/tcp/device.cc
index daf0c2fb1..be9b19edf 100644
--- a/gloo/transport/tcp/device.cc
+++ b/gloo/transport/tcp/device.cc
@@ -15,9 +15,9 @@
 #include <array>
 #include <iostream>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
 #include "gloo/common/linux.h"
-#include "gloo/common/logging.h"
 #include "gloo/common/utils.h"
 #include "gloo/transport/tcp/context.h"
 #include "gloo/transport/tcp/helpers.h"
diff --git a/gloo/transport/tcp/helpers.cc b/gloo/transport/tcp/helpers.cc
index c403996b4..e57ccadc0 100644
--- a/gloo/transport/tcp/helpers.cc
+++ b/gloo/transport/tcp/helpers.cc
@@ -1,4 +1,7 @@
-#include <gloo/transport/tcp/helpers.h>
+#include "gloo/transport/tcp/helpers.h"
+#include "gloo/common/log.h"
+#include "gloo/transport/tcp/debug_data.h"
+#include "gloo/transport/tcp/loop.h"
 
 namespace gloo {
 namespace transport {
@@ -16,6 +19,49 @@ void connectLoop(
   x->run(loop);
 }
 
+void ConnectOperation::handleEvents(Loop& loop, int /*events*/) {
+  // Hold a reference to this object to keep it alive until the
+  // callback is called.
+  auto leak = shared_from_this();
+  loop.unregisterDescriptor(socket_->fd(), this);
+
+  int result;
+  socklen_t result_len = sizeof(result);
+  if (getsockopt(socket_->fd(), SOL_SOCKET, SO_ERROR, &result, &result_len) <
+      0) {
+    fn_(loop, socket_, SystemError("getsockopt", errno, remote_));
+    return;
+  }
+  if (result != 0) {
+    SystemError e("SO_ERROR", result, remote_);
+    bool willRetry =
+        std::chrono::steady_clock::now() < deadline_ && retry_++ < maxRetries_;
+
+    auto debugData = ConnectDebugData{
+        retry_,
+        maxRetries_,
+        willRetry,
+        rank_,
+        size_,
+        e.what(),
+        remote_.str(),
+        socket_->sockName().str(),
+    };
+    GLOO_WARN("{}", debugData);
+
+    // check deadline
+    if (willRetry) {
+      run(loop);
+    } else {
+      fn_(loop, socket_, TimeoutError("timed out connecting: " + e.what()));
+    }
+
+    return;
+  }
+
+  fn_(loop, socket_, Error::kSuccess);
+}
+
 } // namespace tcp
 } // namespace transport
 } // namespace gloo
diff --git a/gloo/transport/tcp/helpers.h b/gloo/transport/tcp/helpers.h
index c75993590..14329a4e9 100644
--- a/gloo/transport/tcp/helpers.h
+++ b/gloo/transport/tcp/helpers.h
@@ -11,16 +11,11 @@
 #include <functional>
 #include <memory>
 
-#include <gloo/common/logging.h>
-#include <gloo/transport/tcp/debug_data.h>
-#include <gloo/transport/tcp/error.h>
-#include <gloo/transport/tcp/loop.h>
-#include <gloo/transport/tcp/socket.h>
-#include "gloo/transport/tcp/debug_logger.h" // @manual=//gloo:debug_logger
+#include "gloo/transport/tcp/error.h"
+#include "gloo/transport/tcp/loop.h"
+#include "gloo/transport/tcp/socket.h"
 
-namespace gloo {
-namespace transport {
-namespace tcp {
+namespace gloo::transport::tcp {
 
 // ReadValueOperation asynchronously reads a value of type T from the
 // socket specified at construction. Upon completion or error, the
@@ -171,48 +166,7 @@ class ConnectOperation final
         this->shared_from_this());
   }
 
-  void handleEvents(Loop& loop, int /*events*/) override {
-    // Hold a reference to this object to keep it alive until the
-    // callback is called.
-    auto leak = shared_from_this();
-    loop.unregisterDescriptor(socket_->fd(), this);
-
-    int result;
-    socklen_t result_len = sizeof(result);
-    if (getsockopt(socket_->fd(), SOL_SOCKET, SO_ERROR, &result, &result_len) <
-        0) {
-      fn_(loop, socket_, SystemError("getsockopt", errno, remote_));
-      return;
-    }
-    if (result != 0) {
-      SystemError e("SO_ERROR", result, remote_);
-      bool willRetry = std::chrono::steady_clock::now() < deadline_ &&
-          retry_++ < maxRetries_;
-
-      auto debugData = ConnectDebugData{
-          retry_,
-          maxRetries_,
-          willRetry,
-          rank_,
-          size_,
-          e.what(),
-          remote_.str(),
-          socket_->sockName().str(),
-      };
-      DebugLogger::log(debugData);
-
-      // check deadline
-      if (willRetry) {
-        run(loop);
-      } else {
-        fn_(loop, socket_, TimeoutError("timed out connecting: " + e.what()));
-      }
-
-      return;
-    }
-
-    fn_(loop, socket_, Error::kSuccess);
-  }
+  void handleEvents(Loop& loop, int /*events*/) override;
 
  private:
   const Address remote_;
@@ -235,6 +189,4 @@ void connectLoop(
     std::chrono::milliseconds timeout,
     typename ConnectOperation::callback_t fn);
 
-} // namespace tcp
-} // namespace transport
-} // namespace gloo
+} // namespace gloo::transport::tcp
diff --git a/gloo/transport/tcp/listener.cc b/gloo/transport/tcp/listener.cc
index 325fe0ffc..409a9a3f6 100644
--- a/gloo/transport/tcp/listener.cc
+++ b/gloo/transport/tcp/listener.cc
@@ -12,7 +12,7 @@
 #include <string.h>
 
 #include <gloo/common/common.h>
-#include <gloo/common/logging.h>
+#include <gloo/common/enforce.h>
 #include <gloo/common/utils.h>
 #include <gloo/transport/tcp/helpers.h>
 #
diff --git a/gloo/transport/tcp/loop.cc b/gloo/transport/tcp/loop.cc
index dca13e33f..613b92a48 100644
--- a/gloo/transport/tcp/loop.cc
+++ b/gloo/transport/tcp/loop.cc
@@ -14,8 +14,8 @@
 
 #include <array>
 
+#include <gloo/common/enforce.h>
 #include <gloo/common/error.h>
-#include <gloo/common/logging.h>
 
 #if defined(__SANITIZE_THREAD__)
 #define TSAN_ENABLED
diff --git a/gloo/transport/tcp/pair.cc b/gloo/transport/tcp/pair.cc
index 030778c0b..95705b83f 100644
--- a/gloo/transport/tcp/pair.cc
+++ b/gloo/transport/tcp/pair.cc
@@ -22,8 +22,8 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/transport/tcp/buffer.h"
 #include "gloo/transport/tcp/context.h"
 #include "gloo/transport/tcp/unbound_buffer.h"
diff --git a/gloo/transport/tcp/socket.cc b/gloo/transport/tcp/socket.cc
index 1b1270653..4c304b319 100644
--- a/gloo/transport/tcp/socket.cc
+++ b/gloo/transport/tcp/socket.cc
@@ -13,7 +13,7 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <gloo/common/logging.h>
+#include <gloo/common/enforce.h>
 
 namespace gloo {
 namespace transport {
diff --git a/gloo/transport/tcp/tls/context.cc b/gloo/transport/tcp/tls/context.cc
index 141fdac3b..06a819097 100644
--- a/gloo/transport/tcp/tls/context.cc
+++ b/gloo/transport/tcp/tls/context.cc
@@ -8,7 +8,7 @@
 
 #include "gloo/transport/tcp/tls/context.h"
 
-#include "gloo/common/logging.h"
+#include "gloo/common/enforce.h"
 #include "gloo/transport/tcp/tls/device.h"
 #include "gloo/transport/tcp/tls/openssl.h"
 #include "gloo/transport/tcp/tls/pair.h"
diff --git a/gloo/transport/tcp/tls/pair.cc b/gloo/transport/tcp/tls/pair.cc
index 3e0fcfde3..7c096ea8b 100644
--- a/gloo/transport/tcp/tls/pair.cc
+++ b/gloo/transport/tcp/tls/pair.cc
@@ -8,8 +8,8 @@
 
 #include "gloo/transport/tcp/tls/pair.h"
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/transport/tcp/buffer.h"
 #include "gloo/transport/tcp/tls/context.h"
 #include "gloo/transport/tcp/tls/device.h"
diff --git a/gloo/transport/tcp/unbound_buffer.cc b/gloo/transport/tcp/unbound_buffer.cc
index b8cac4679..59b484b30 100644
--- a/gloo/transport/tcp/unbound_buffer.cc
+++ b/gloo/transport/tcp/unbound_buffer.cc
@@ -8,8 +8,8 @@
 
 #include "gloo/transport/tcp/unbound_buffer.h"
 
+#include "gloo/common/enforce.h"
 #include "gloo/common/error.h"
-#include "gloo/common/logging.h"
 #include "gloo/transport/tcp/context.h"
 
 namespace gloo {
diff --git a/gloo/transport/uv/address.cc b/gloo/transport/uv/address.cc
index 9b69b9ece..f85d49b46 100644
--- a/gloo/transport/uv/address.cc
+++ b/gloo/transport/uv/address.cc
@@ -12,7 +12,7 @@
 
 #include <uv.h>
 
-#include <gloo/common/logging.h>
+#include <gloo/common/enforce.h>
 
 namespace gloo {
 namespace transport {
diff --git a/gloo/transport/uv/context.cc b/gloo/transport/uv/context.cc
index 606bc95af..1b342854f 100644
--- a/gloo/transport/uv/context.cc
+++ b/gloo/transport/uv/context.cc
@@ -8,8 +8,8 @@
 
 #include <gloo/transport/uv/context.h>
 
+#include <gloo/common/enforce.h>
 #include <gloo/common/error.h>
-#include <gloo/common/logging.h>
 #include <gloo/transport/uv/device.h>
 #include <gloo/transport/uv/pair.h>
 #include <gloo/transport/uv/unbound_buffer.h>
diff --git a/gloo/transport/uv/device.cc b/gloo/transport/uv/device.cc
index 1dc986433..c6af3fefe 100644
--- a/gloo/transport/uv/device.cc
+++ b/gloo/transport/uv/device.cc
@@ -22,7 +22,7 @@
 #else
 #include <gloo/common/win.h> // @manual
 #endif
-#include <gloo/common/logging.h>
+#include <gloo/common/enforce.h>
 #include <gloo/transport/uv/common.h>
 #include <gloo/transport/uv/context.h>
 #include <gloo/transport/uv/libuv.h>
diff --git a/gloo/transport/uv/pair.cc b/gloo/transport/uv/pair.cc
index 4db8bf32c..e1fea6839 100644
--- a/gloo/transport/uv/pair.cc
+++ b/gloo/transport/uv/pair.cc
@@ -11,8 +11,8 @@
 #include <cstring>
 #include <iostream>
 
+#include <gloo/common/enforce.h>
 #include <gloo/common/error.h>
-#include <gloo/common/logging.h>
 #include <gloo/transport/uv/common.h>
 #include <gloo/transport/uv/context.h>
 #include <gloo/transport/uv/libuv.h>
diff --git a/gloo/transport/uv/unbound_buffer.cc b/gloo/transport/uv/unbound_buffer.cc
index 593020b3c..f0cebf261 100644
--- a/gloo/transport/uv/unbound_buffer.cc
+++ b/gloo/transport/uv/unbound_buffer.cc
@@ -8,8 +8,8 @@
 
 #include <gloo/transport/uv/unbound_buffer.h>
 
+#include <gloo/common/enforce.h>
 #include <gloo/common/error.h>
-#include <gloo/common/logging.h>
 #include <gloo/transport/uv/context.h>
 
 namespace gloo {
diff --git a/gloo/types.h b/gloo/types.h
index b9cb94680..b88093e80 100644
--- a/gloo/types.h
+++ b/gloo/types.h
@@ -339,4 +339,12 @@ inline float cpu_half2float(float16 h) {
   return *(float*)rp;
 }
 
+/**
+ * @brief Format helper for spdlog/fmt - convert to a float32 and format as
+ * usual
+ */
+inline float format_as(float16 v) {
+  return cpu_half2float(v);
+}
+
 } // namespace gloo
diff --git a/third_party/spdlog b/third_party/spdlog
new file mode 160000
index 000000000..6fa36017c
--- /dev/null
+++ b/third_party/spdlog
@@ -0,0 +1 @@
+Subproject commit 6fa36017cfd5731d617e1a934f0e5ea9c4445b13