CMake modules get installed to a wrong path

[lahwaacz]

When building the ginkgo-hpc-git AUR package, I noticed that it installs the following cmake files:

ginkgo-hpc-git /usr/lib/cmake/
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/GinkgoConfig.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/GinkgoConfigVersion.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/GinkgoTargets-release.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/GinkgoTargets.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/CudaArchitectureSelector.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/FindHWLOC.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/FindNUMA.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/FindPAPI.cmake
ginkgo-hpc-git /usr/lib/cmake/Ginkgo/Modules/Modules/hwloc_helpers.cmake

The Modules/Modules part is most likely a bug which causes the following error when find_package(Ginkgo) is used in another project:

CMake Error at /usr/lib64/cmake/Ginkgo/GinkgoConfig.cmake:187 (find_package):
  By not providing "FindHWLOC.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "HWLOC", but
  CMake did not find one.

  Could not find a package configuration file provided by "HWLOC" with any of
  the following names:

    HWLOCConfig.cmake
    hwloc-config.cmake

  Add the installation prefix of "HWLOC" to CMAKE_PREFIX_PATH or set
  "HWLOC_DIR" to a directory containing one of the above files.  If "HWLOC"
  provides a separate development package or SDK, be sure it has been
  installed.
Call Stack (most recent call first):
  CMakeLists.txt:55 (find_package)


-- Configuring incomplete, errors occurred!

[lahwaacz]

This is still not fixed – the same CMake error appears when one wants to find_package(Ginkgo). The modules now get installed to /usr/lib/cmake/Ginkgo/Modules/ but that path is not searched by find_package by default. I guess you need to set CMAKE_MODULE_PATH from the installed GinkgoConfig.cmake or to install the modules to /usr/share/cmake/Modules/ (and worry about name conflicts with other projects).

[upsj]

Can you check in more detail where this is failing? I can't reproduce it right now in an archlinux docker container (though I didn't use your package to build it, not familiar enough with Arch to do that). We already add the relevant path to the CMAKE_MODULE_PATH, see GinkgoConfig.cmake.in:105

list(APPEND CMAKE_MODULE_PATH "@CMAKE_MODULE_PATH@" "${GINKGO_INSTALL_MODULE_DIR}")

Useful tools are cmake --trace and cmake --trace-expand to debug the execution.

[lahwaacz]

Oh, right. The /usr/lib/cmake/Ginkgo/GinkgoConfig.cmake file in the package I built contains this path:

list(APPEND CMAKE_MODULE_PATH "/build/ginkgo-hpc-git/src/ginkgo/cmake/Modules/" "${GINKGO_INSTALL_MODULE_DIR}")

Now, the first path is wrong – /build/ is the path where the package was built (in a chroot environment) and it does not make sense when the package gets installed. I see you've created #1188 for this.

The "${GINKGO_INSTALL_MODULE_DIR}" path should do the trick, but it does not work. When I manually added message("${CMAKE_MODULE_PATH}"), the variable expanded to

/build/ginkgo-hpc-git/src/ginkgo/cmake/Modules/;/usr/lib64/cmake/Ginkgo/lib/cmake/Ginkgo/Modules

There is string(REPLACE "lib/cmake/Ginkgo" "" GINKGO_INSTALL_PREFIX "${GINKGO_CONFIG_FILE_PATH}") couple of lines above in /usr/lib/cmake/Ginkgo/GinkgoConfig.cmake, but lib64/cmake/Ginkgo should have been stripped...

[upsj]

@lahwaacz if you have a minute, could you try out the linked PR? It should now produce relocatable GinkgoConfig.cmake files

[lahwaacz]

@upsj That seems to fix this 👍