Detect Scip installation in conda environment if SCIPOPTDIR is not defined (#1103)

Co-authored-by: João Dionísio <57299939+Joao-Dionisio@users.noreply.github.com>

Author: mmghannam

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Added basic type stubs to help with IDE autocompletion and type checking.
 - MatrixVariable comparisons (<=, >=, ==) now support numpy's broadcast feature.
 - Added methods: getMaxDepth(), getPlungeDepth(), getLowerbound(), getCutoffbound(), getNNodeLPIterations(), getNStrongbranchLPIterations().
+- setup.py now automatically detects conda environments when SCIPOPTDIR is not defined.
 ### Fixed
 - Implemented all binary operations between MatrixExpr and GenExpr
 - Fixed the type of @ matrix operation result from MatrixVariable to MatrixExpr.

INSTALL.md

@@ -32,6 +32,8 @@ you need to specify the install location using the environment variable
     `set SCIPOPTDIR=<path_to_install_dir>` (**cmd**, **Cmder**, **WSL**)\
     `$Env:SCIPOPTDIR = "<path_to_install_dir>"` (**powershell**)
 
+**Note:** If `SCIPOPTDIR` is not set, the setup script will automatically attempt to detect a conda environment (via the `CONDA_PREFIX` environment variable) and use it if available. If no conda environment is detected, it will fall back to searching global installation paths.
+
 `SCIPOPTDIR` needs to have a subdirectory `lib` that contains the
 library, e.g. `libscip.so` (for Linux) and a subdirectory `include` that
 contains the corresponding header files:

setup.py

@@ -7,16 +7,28 @@
 extra_compile_args = []
 extra_link_args = []
 
-# if SCIPOPTDIR is not set, we assume that SCIP is installed globally
+# if SCIPOPTDIR is not set, try to detect conda environment, otherwise assume global installation
 if not scipoptdir:
-    if platform.system() == "Darwin":
-        includedir = "/usr/local/include"
-        libdir = "/usr/local/lib"
+    # check if we're in a conda environment
+    conda_prefix = os.environ.get("CONDA_PREFIX", "").strip('"')
+
+    if conda_prefix and os.path.exists(os.path.join(conda_prefix, "include")):
+        includedir = os.path.join(conda_prefix, "include")
+        libdir = os.path.join(conda_prefix, "lib")
+        libname = "libscip" if platform.system() == "Windows" else "scip"
+        print(f"Detected conda environment at {conda_prefix}.")
+        print(f"Using include path {includedir}.")
+        print(f"Using library directory {libdir}.\n")
     else:
-        includedir = "."
-        libdir = "."
-    libname = "libscip" if platform.system() in ["Windows"] else "scip"
-    print("Assuming that SCIP is installed globally, because SCIPOPTDIR is undefined.\n")
+        # fall back to global installation
+        if platform.system() == "Darwin":
+            includedir = "/usr/local/include"
+            libdir = "/usr/local/lib"
+        else:
+            includedir = "."
+            libdir = "."
+        libname = "libscip" if platform.system() == "Windows" else "scip"
+        print("Assuming that SCIP is installed globally, because SCIPOPTDIR is undefined.\n")
 
 else:
 
@@ -51,7 +63,7 @@
     else:
         # assume that SCIP is installed on the system
         libdir = os.path.abspath(os.path.join(scipoptdir, "lib"))
-        libname = "libscip" if platform.system() in ["Windows"] else "scip"
+        libname = "libscip" if platform.system() == "Windows" else "scip"
 
     print(f"Using include path {includedir}.")
     print(f"Using SCIP library {libname} at {libdir}.\n")