The patch does not work. I thought this was due to it returning the .cmake files themselves and not the directory containing them. Here, for instance, it contains /gnu/store/h30r6z3fc67h8557kd63vjjdlfpc58wj-libqtxdg-1.1.0/share/cmake/qt5xdg/qt5xdg-config.cmake Inside the build directory, I tried an export CMAKE_MODULE_PATH=/gnu/store/h30r6z3fc67h8557kd63vjjdlfpc58wj-libqtxdg-1.1.0/share/cmake/qt5xdg with the same error message.
Then I followed the advice given on screen and set export CMAKE_PREFIX_PATH=/gnu/store/h30r6z3fc67h8557kd63vjjdlfpc58wj-libqtxdg-1.1.0 which worked. export Qt5Xdg_DIR=/gnu/store/h30r6z3fc67h8557kd63vjjdlfpc58wj-libqtxdg-1.1.0/share/cmake/qt5xdg worked as well. But I do not see how to implement this kind of package specific path in guix. The following explains why CMAKE_MODULE_PATH has no effect here: http://www.cmake.org/cmake/help/v3.0/command/find_package.html Apparently, there is a "module mode" and a "config mode". The first one uses CMAKE_MODULE_PATH and looks for files called FindPACKAGE.cmake. We are in the second case here, where a file PACKAGEConfig.cmake or package-config.cmake is looked for. Further below on that page, it is explained where these config files are looked for. On unix like systems, this is <prefix>/(lib/<arch>|lib|share)/cmake/<name>*/ <prefix>/(lib/<arch>|lib|share)/<name>*/ <prefix>/(lib/<arch>|lib|share)/<name>*/(cmake|CMake)/ The <prefix> part can be set by CMAKE_PREFIX_PATH. What would be desirable is the following: In the definition of a search path, we need an additional transformation (if it is not already there). We need to look for the regular expression (.+)/(lib|lib64|share)/.+\.cmake$ or maybe (.+)/(lib|lib/[^/]+|share)/.+\.cmake$ and put \1 into CMAKE_PREFIX_PATH. I think that would also make the lines (setenv "CMAKE_LIBRARY_PATH" (getenv "LIBRARY_PATH")) (setenv "CMAKE_INCLUDE_PATH" (getenv "CPATH")) in guix/build/cmake-build-system obsolete. Concerning the "lib64" part, I still have doubts. The documentation speaks of "lib/<arch>"; yet, there are packages which install into "lib64" (like libqtxdg, needed for liblxqt, which triggered this discussion). So if the suggestion above does not work, we can in a second step try to play with CMAKE_INSTALL_LIBDIR. Andreas
