cmake: don't set CMAKE_FIND_ROOT_PATH in toolchain files

When CMAKE_FIND_ROOT_PATH and CMAKE_PREFIX_PATH are both set,
cmake concatenates them together, instead of using CMAKE_PREFIX_PATH as
a full path like we want. Turns out CMAKE_FIND_ROOT_PATH didn't do
anything anyway, so get rid of that.

Author: slipher

cmake/cross-toolchain-mingw32.cmake

@@ -7,10 +7,8 @@ set( CMAKE_C_COMPILER i686-w64-mingw32-gcc )
 set( CMAKE_CXX_COMPILER i686-w64-mingw32-g++ )
 set( CMAKE_RC_COMPILER i686-w64-mingw32-windres )
 
-# Target prefix
-set( CMAKE_FIND_ROOT_PATH /usr/i686-w64-mingw32;${CMAKE_PREFIX_PATH} )
-
 # Find programs using host paths and headers/libraries using target paths
+# FIXME: not respected when cmake invokes pkg-config
 set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER )
 set( CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY )
 set( CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY )

cmake/cross-toolchain-mingw64.cmake

@@ -7,10 +7,8 @@ set( CMAKE_C_COMPILER x86_64-w64-mingw32-gcc )
 set( CMAKE_CXX_COMPILER x86_64-w64-mingw32-g++ )
 set( CMAKE_RC_COMPILER x86_64-w64-mingw32-windres )
 
-# Target prefix
-set( CMAKE_FIND_ROOT_PATH /usr/x86_64-w64-mingw32;${CMAKE_PREFIX_PATH} )
-
 # Find programs using host paths and headers/libraries using target paths
+# FIXME: not respected when cmake invokes pkg-config
 set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER )
 set( CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY )
 set( CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY )

external_deps/build.sh

@@ -260,8 +260,8 @@ log_build() {
 	esac
 }
 
-# Build pkg-config
-# Still needed, at least on macos, for opusfile
+# Build pkg-config, needed for opusfile
+# As a host-mode dependency it must be provided by the system when cross-compiling.
 build_pkgconfig() {
 	local dir_name="pkg-config-${PKGCONFIG_VERSION}"
 	local archive_name="${dir_name}.tar.gz"