cmake: Fail if Libmultiprocess is missing when WITH_MULTIPROCESS=ON #31709

1. 
   hebasto commented at 5:35 pm on January 22, 2025: member

   Fixes #31708:

    0$ cmake -B build -DWITH_MULTIPROCESS=ON
    1-- The CXX compiler identification is GNU 13.3.0
    2-- Detecting CXX compiler ABI info
    3-- Detecting CXX compiler ABI info - done
    4-- Check for working CXX compiler: /usr/bin/c++ - skipped
    5-- Detecting CXX compile features
    6-- Detecting CXX compile features - done
    7-- Found SQLite3: /usr/include (found suitable version "3.45.1", minimum required is "3.7.17") 
    8CMake Error at CMakeLists.txt:146 (find_package):
    9  By not providing "FindLibmultiprocess.cmake" in CMAKE_MODULE_PATH this
   10  project has asked CMake to find a package configuration file provided by
   11  "Libmultiprocess", but CMake did not find one.
   12
   13  Could not find a package configuration file provided by "Libmultiprocess"
   14  with any of the following names:
   15
   16    LibmultiprocessConfig.cmake
   17    libmultiprocess-config.cmake
   18
   19  Add the installation prefix of "Libmultiprocess" to CMAKE_PREFIX_PATH or
   20  set "Libmultiprocess_DIR" to a directory containing one of the above files.
   21  If "Libmultiprocess" provides a separate development package or SDK, be
   22  sure it has been installed.
   23
   24
   25-- Configuring incomplete, errors occurred!
   

2. cmake: Fail if `Libmultiprocess` is missing when `WITH_MULTIPROCESS=ON` c31166ac77
3. 
   DrahtBot commented at 5:35 pm on January 22, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/31709.

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4. DrahtBot added the label Build system on Jan 22, 2025
5. hebasto added this to the milestone 29.0 on Jan 22, 2025
6. vasild approved
7. 
   vasild commented at 6:00 pm on January 22, 2025: contributor

   ACK c31166ac77af8fbdc9012999b345540fe88cc394

   I just encountered the current behavior in master today. It wasn’t unmanageable because the error message is quite clear. Anyway I agree it is better to flag the library as required which turns the warning into an error:

    0@@ -1,23 +1,18 @@
    1-CMake Warning at CMakeLists.txt:146 (find_package):
    2+CMake Error at CMakeLists.txt:146 (find_package):
    3   By not providing "FindLibmultiprocess.cmake" in CMAKE_MODULE_PATH this
    4   project has asked CMake to find a package configuration file provided by
    5   "Libmultiprocess", but CMake did not find one.
    6 
    7   Could not find a package configuration file provided by "Libmultiprocess"
    8   with any of the following names:
    9 
   10     LibmultiprocessConfig.cmake
   11     libmultiprocess-config.cmake
   12 
   13   Add the installation prefix of "Libmultiprocess" to CMAKE_PREFIX_PATH or
   14   set "Libmultiprocess_DIR" to a directory containing one of the above files.
   15   If "Libmultiprocess" provides a separate development package or SDK, be
   16   sure it has been installed.
   17-
   18-
   19--- Could NOT find LibmultiprocessNative (missing: LibmultiprocessNative_DIR)
   20-CMake Error at src/ipc/CMakeLists.txt:12 (target_capnp_sources):
   21-  Unknown CMake command "target_capnp_sources".
   22 
   23 
   24 -- Configuring incomplete, errors occurred!
   

8. ryanofsky approved
9. 
   ryanofsky commented at 6:13 pm on January 22, 2025: contributor

   Code review ACK c31166ac77af8fbdc9012999b345540fe88cc394
10. TheCharlatan approved
11. 
    TheCharlatan commented at 7:44 am on January 23, 2025: contributor

    ACK c31166ac77af8fbdc9012999b345540fe88cc394
12. fanquake merged this on Jan 23, 2025
13. fanquake closed this on Jan 23, 2025

    ---

14. hebasto deleted the branch on Jan 23, 2025

Contributors
hebasto DrahtBot vasild ryanofsky TheCharlatan

Labels
Build system

Milestone
29.0