CMake: `cmake_pkg_config` uses wrong path

[capitalistspz]

Bug Report

What's the issue you encountered?

CMake 3.31's cmake_pkg_config uses host paths instead of the devkitPro paths.

How can the issue be reproduced?

CMakeLists.txt

cmake_minimum_required(VERSION 3.31)
project(test)

cmake_pkg_config(EXTRACT freetype2 REQUIRED)
message(STATUS "${CMAKE_PKG_CONFIG_INCLUDES}")

find_package(PkgConfig REQUIRED QUIET)
pkg_search_module(freetype2 REQUIRED QUIET "freetype2")
message(STATUS "${freetype2_INCLUDEDIR}")

$ $DEVKITPRO/portlibs/wiiu/bin/powerpc-eabi-cmake .
-- -I/usr/include/freetype2
-- /opt/devkitpro/portlibs/ppc/include
-- Configuring done (0.0s)
-- Generating done (0.0s)

Environment?

EndeavourOS Linux x86_64

[carstene1ns]

This looks like a bug in CMake¹. It might get fixed in the future.
For a short term solution, overwriting CMAKE_PKG_CONFIG_PC_LIB_DIRS² works, but is only available in 4+.
CMake also ships a find module which works as well.

cmake_minimum_required(VERSION 3.31)
project(test)

set(CMAKE_PKG_CONFIG_PC_LIB_DIRS "/opt/devkitpro/portlibs/ppc/lib/pkgconfig")

cmake_pkg_config(EXTRACT freetype2 REQUIRED)
message(STATUS "new pkgconfig ${CMAKE_PKG_CONFIG_INCLUDES}")

find_package(PkgConfig REQUIRED QUIET)
pkg_search_module(freetype2 REQUIRED QUIET "freetype2")
message(STATUS "old pkgconfig ${freetype2_INCLUDE_DIRS}")

find_package(Freetype REQUIRED QUIET)
message(STATUS "find module ${FREETYPE_INCLUDE_DIRS}")

-- new pkgconfig -I/opt/devkitpro/portlibs/ppc/include/freetype2
-- old pkgconfig /opt/devkitpro/portlibs/ppc/include/freetype2;/opt/devkitpro/portlibs/ppc/include/libpng16;/opt/devkitpro/portlibs/ppc/include
-- find module /opt/devkitpro/portlibs/ppc/include/freetype2

Footnotes

1. https://gitlab.kitware.com/cmake/cmake/-/work_items/27437 ↩

2. https://cmake.org/cmake/help/v4.0/variable/CMAKE_PKG_CONFIG_PC_LIB_DIRS.html ↩

[capitalistspz]

The last message on the cmake work item suggests that they'll use the output of --variable=pc_path pkg-config or --dump-personality, to obtain the paths, but currently:

$ $DEVKITPRO/portlibs/ppc/bin/powerpc-eabi-pkg-config --variable=pc_path pkg-config
/usr/lib/pkgconfig:/usr/share/pkgconfig

$ $DEVKITPRO/portlibs/ppc/bin/powerpc-eabi-pkg-config --dump-personality
Triplet: default
DefaultSearchPaths: /usr/lib/pkgconfig /usr/share/pkgconfig 
SystemIncludePaths: /usr/include 
SystemLibraryPaths: /usr/lib 

So, if we're going to wait for CMake to fix it, the <triplet>-pkg-config scripts need to be adjusted to return devkitPro paths for these.