pkg-config does not work on conda

[ischoegl]

Problem description

An attempt to compile the very simple C++ program using the pkg-config route fails.

Steps to reproduce

1. Saved very simple C++ program as simple.cpp
2. Run the following

% export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/lib
% export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/lib/pkgconfig
% g++ simple.cpp -o myProgram $(pkg-config --cflags --libs cantera)
% ./myProgram
dyld[92219]: Library not loaded: @rpath/libsundials_cvodes.6.dylib
  Referenced from: <E62AB15F-607D-3047-996E-A59885DCC71C> /Volumes/Data/work/GitHub/cantera/myProgram
  Reason: tried: '/System/Volumes/Preboot/Cryptexes/OS@rpath/libsundials_cvodes.6.dylib' (no such file), '/usr/local/lib/libsundials_cvodes.6.dylib' (no such file), '/usr/lib/libsundials_cvodes.6.dylib' (no such file, not in dyld cache)
zsh: abort      ./myProgram

System information

• Cantera version: 3.0.0a3
• OS: macOS
• Python/MATLAB/other software versions: conda environment

Attachments

cantera.pc has the following content:

prefix=/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev
exec_prefix=${prefix}/bin
libdir=${prefix}/lib
includedir=${prefix}/include

Name: Cantera
Description: Cantera library
URL: https://cantera.org
Version: 3.0.0a3

Libs: -L${libdir} -L/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/lib -L/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/lib/python3.10/config-3.10-darwin -L/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/lib -lcantera -lsundials_cvodes -lsundials_ida -lsundials_nvecserial -lsundials_sunlinsollapackdense -lsundials_sunlinsollapackband -lfmt -lyaml-cpp -lpython3.10 -ldl
Cflags: -std=c++14 -framework Accelerate -I${includedir} -I/opt/homebrew/Caskroom/miniforge/base/envs/cantera-dev/include -I

Additional context

Issue arose in the context of #1385

[ischoegl]

With shared libraries introduced in Cantera 3.0.0a4, the library can now be linked with cantera_shared, which causes a somewhat different error:

% g++ simple.cpp -o myProgram $(pkg-config --cflags --libs cantera_shared)
Package cantera_shared was not found in the pkg-config search path.
Perhaps you should add the directory containing `cantera_shared.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cantera_shared' found
simple.cpp:1:10: fatal error: 'cantera/base/Solution.h' file not found
#include "cantera/base/Solution.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

A fix requires renaming cantera.pc to cantera_shared.pc, and using shared libraries rather than static libraries.

[speth]

Given the improvements to handling the shared library, and the fact that using it is required for features like ExtensibleRate, I'm thinking we should just have pkg-config --libs cantera return flags suitable for linking to the shared library.

[speth]

After some recent updates, pkg-config mostly works. That is, the command:

g++ kinetics1.cpp -o kinetics1 $(pkg-config --cflags --libs cantera)

produces an executable with no warnings. Two minor issues remain.

1. Running the program requires providing information about the library path, either at run time:

LD_LIBRARY_PATH=$CONDA_PREFIX/lib ./kinetics1

or by recompiling with the RPATH embedded:

g++ kinetics1.cpp -o kinetics1 $(pkg-config --cflags --libs cantera) -Wl,-rpath,$CONDA_PREFIX/lib

This second solution can be baked into the cantera.pc file, of course.

Second, a path that only existed on the system where the package was built ends up in the cantera.pc file as an "include directory, e.g. -isystem /usr/share/miniconda3/conda-bld/cantera-recipe_1687996688861/_build_env/include. It would be nice to get rid of this, but it doesn't actually hurt anything.