support building on OpenBSD

[unix-supremacist]

following https://github.com/HarbourMasters/Shipwright/blob/develop/BUILDING.md#linux (linux is the most similar)
when you get to cmake -H. -Bbuild-cmake -GNinja it can't find the system sdl2 it seems.

unix E[0] /home/unix/Source/Shipwright/ ➜ cmake -H. -Bbuild-cmake -GNinja
-- OpenBSD
-- Linking against dependent libraries statically
-- Using the multi-header code from /home/unix/Source/Shipwright/libultraship/extern/nlohmann-json/include/
-- Testing if -Werror=pointer-arith can be used -- compiles
-- Testing if -Werror=implicit-function-declaration can be used -- compiles
-- Testing if -fno-strict-aliasing can be used -- compiles
-- Using raylib's GLFW
-- Using X11 for window creation
-- Audio Backend: miniaudio
-- Building raylib static library
-- Generated build type: Debug
-- Compiling with the flags:
--   PLATFORM=PLATFORM_DESKTOP
--   GRAPHICS=GRAPHICS_API_OPENGL_33
-- Configuring done
CMake Error at libultraship/extern/CMakeLists.txt:73 (target_link_libraries):
  Target "ImGui" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



CMake Error at soh/CMakeLists.txt:2100 (target_link_libraries):
  Target "soh" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.

the pkg is installed

unix E[0] /home/unix/Source/Shipwright/ ➜ pkg_info | grep sdl2
sdl2-2.0.20p0       cross-platform multimedia library

the cmake files for SDL2 seem to be in the proper /usr/local/lib/cmake/SDL2/ location.

unix E[0] /home/unix/Source/Shipwright/ ➜ ls /usr/local/lib/cmake/SDL2/
.                          ..                         sdl2-config-version.cmake  sdl2-config.cmake

i have no idea what could be causing this issue as it seems to be entirely dependency related, i might be missing something with how cmake handles dependencies but i'm not sure

[briaguya0]

i'm pretty sure you need the sdl2 development package to ensure the headers are available at build time (on debian that's libsdl2-dev), i'm not sure what the openbsd equivalent of that would be

[unix-supremacist]

sorry for the late response, there doesnt seem to be a separate package for my system, and in /usr/local/include/SDL2/ there seems to be all the appropiate headers for SDL2

unix E[0] /home/unix/ ➜ /usr/local/include/SDL2/
SDL.h                         SDL_haptic.h                  SDL_opengl.h                  SDL_scancode.h                SDL_test_log.h
SDL_assert.h                  SDL_hidapi.h                  SDL_opengl_glext.h            SDL_sensor.h                  SDL_test_md5.h
SDL_atomic.h                  SDL_hints.h                   SDL_opengles.h                SDL_shape.h                   SDL_test_memory.h
SDL_audio.h                   SDL_joystick.h                SDL_opengles2.h               SDL_stdinc.h                  SDL_test_random.h
SDL_bits.h                    SDL_keyboard.h                SDL_opengles2_gl2.h           SDL_surface.h                 SDL_thread.h
SDL_blendmode.h               SDL_keycode.h                 SDL_opengles2_gl2ext.h        SDL_system.h                  SDL_timer.h
SDL_clipboard.h               SDL_loadso.h                  SDL_opengles2_gl2platform.h   SDL_syswm.h                   SDL_touch.h
SDL_config.h                  SDL_locale.h                  SDL_opengles2_khrplatform.h   SDL_test.h                    SDL_types.h
SDL_cpuinfo.h                 SDL_log.h                     SDL_pixels.h                  SDL_test_assert.h             SDL_version.h
SDL_egl.h                     SDL_main.h                    SDL_platform.h                SDL_test_common.h             SDL_video.h
SDL_endian.h                  SDL_messagebox.h              SDL_power.h                   SDL_test_compare.h            SDL_vulkan.h
SDL_error.h                   SDL_metal.h                   SDL_quit.h                    SDL_test_crc32.h              begin_code.h
SDL_events.h                  SDL_misc.h                    SDL_rect.h                    SDL_test_font.h               close_code.h
SDL_filesystem.h              SDL_mouse.h                   SDL_render.h                  SDL_test_fuzzer.h
SDL_gamecontroller.h          SDL_mutex.h                   SDL_revision.h                SDL_test_harness.h
SDL_gesture.h                 SDL_name.h                    SDL_rwops.h                   SDL_test_images.h

maybe im missing something but this seems right?

also the proper .a/.so files

unix E[130] /home/unix/ ➜ ls /usr/local/lib/ | grep SDL2
libSDL2.a
libSDL2.la
libSDL2.so.0.11
libSDL2_test.a
libSDL2_test.la
libSDL2main.a
libSDL2main.la

[leggettc18]

I was in the middle of typing a response when you posted your last comment, where I was going to suggest you check those directories and yep, seems like everything is there. I'm noticing they are in /usr/local/, is that normal for BSD, and does cmake check that directory by default for finding the -config.cmake files? I imagine it would, just a key difference I noticed.

It's not likely the cause of this particular issue, but you seem to have version 2.0.20 installed while our BUILDING.md indicates you need at least 2.0.22. It will probably be just fine, but if you do have any weird bugs that nobody can replicate later that could be the cause.

[unix-supremacist]

as far as the update, i just checked and theres a new sdl2 version in ports, but the package repo doesn't seem updated, i'll look at building and installing that if i need to.

and yes /usr/local/ is normal on bsd for a lot of things, linux is different i forgot why, it may symlink those directories elsewhere don't remember

i don't honestly know if cmake checks those directories for files, but i assume since other projects work, and the openbsd package installs the cmake files to that directory, so i assume it would

[leggettc18]

Ok, I have one thing I'd like you to try, I'm not quite sure if it will make any difference. In soh/CMakeLists.txt on line 2063, change that line to read find_package(SDL2 CONFIG). CMake is supposed to fall back to config mode if module mode doesn't work, but this way we can at least be certain it's looking for the -config.cmake files correctly (which is what you have on your system) instead of trying to find a Find<package>.cmake file.

[leggettc18]

You could also try adding the flag -DCMAKE_PREFIX_PATH=/usr/local/lib to ensure it's looking in /usr/local correctly, or -DCMAKE_MODULE_PATH=/usr/local/lib/cmake/SDL2, but the method in my previous comment would be preferred, as we can easily incorporate that into our CMakeLists.

[leggettc18]

Oh and I should clarify, changing just that one line I mentioned may not make it configure successfully, but it should get rid of one of those two errors if that's what the issue was.

[unix-supremacist]

doing all three gives the exact sane results unfortunately,

unix E[1] /home/unix/Source/Shipwright/ ➜ cmake -H. -Bbuild-cmake -GNinja -DCMAKE_MODULE_PATH=/usr/local/lib/cmake/SDL2
-- OpenBSD
-- Linking against dependent libraries statically
-- Using the multi-header code from /home/unix/Source/Shipwright/libultraship/extern/nlohmann-json/include/
-- Testing if -Werror=pointer-arith can be used -- compiles
-- Testing if -Werror=implicit-function-declaration can be used -- compiles
-- Testing if -fno-strict-aliasing can be used -- compiles
-- Using raylib's GLFW
-- Using X11 for window creation
-- Audio Backend: miniaudio
-- Building raylib static library
-- Generated build type: Debug
-- Compiling with the flags:
--   PLATFORM=PLATFORM_DESKTOP
--   GRAPHICS=GRAPHICS_API_OPENGL_33
-- Configuring done
CMake Error at libultraship/extern/CMakeLists.txt:73 (target_link_libraries):
  Target "ImGui" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



CMake Error at soh/CMakeLists.txt:2100 (target_link_libraries):
  Target "soh" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.

[unix-supremacist]

didn't mean to close it oops, it for some reason enter closed it, anyway i meant to say as an example that is the results of one but i tried all three

[unix-supremacist]

oh and from what i understand isn't the SDL2::SDL2 call looking for specifically the SDL2 shared object? i noticed libSDL2.so.0.11
was sort of a weird name and i was wondering if that could be the issue?

[leggettc18]

No, it should be linking the library statically and thus should be looking for libSDL2.a I believe. And regardless I've got similarly weird names on Linux, although now that you bring it up I do see symlinks for names without those numbers on Linux. Hmmm, perhaps for BSD we need to be linking SDL2::SDL2-static? If you could try that, line 2069 of soh/CMakeLists.txt is the one to find. As before, that alone won't fix the build but it should remove one of the errors in your logs and give us a clue how to proceed.

Thanks for your patience in testing thus far, I don't think anyone on the dev team has a BSD system ready to go, so you being willing to try my suggestions is a huge help.

[unix-supremacist]

SDL2-static gives this

unix E[0] /home/unix/Source/Shipwright/ ➜ cmake -H. -Bbuild-cmake -GNinja
-- OpenBSD
-- Linking against dependent libraries statically
-- Using the multi-header code from /home/unix/Source/Shipwright/libultraship/extern/nlohmann-json/include/
CMake Warning at soh/CMakeLists.txt:2063 (find_package):
  By not providing "FindSDL2-static.cmake" in CMAKE_MODULE_PATH this project
  has asked CMake to find a package configuration file provided by
  "SDL2-static", but CMake did not find one.

  Could not find a package configuration file provided by "SDL2-static" with
  any of the following names:

    SDL2-staticConfig.cmake
    sdl2-static-config.cmake

  Add the installation prefix of "SDL2-static" to CMAKE_PREFIX_PATH or set
  "SDL2-static_DIR" to a directory containing one of the above files.  If
  "SDL2-static" provides a separate development package or SDK, be sure it
  has been installed.


-- Testing if -Werror=pointer-arith can be used -- compiles
-- Testing if -Werror=implicit-function-declaration can be used -- compiles
-- Testing if -fno-strict-aliasing can be used -- compiles
-- Using raylib's GLFW
-- Using X11 for window creation
-- Audio Backend: miniaudio
-- Building raylib static library
-- Generated build type: Debug
-- Compiling with the flags:
--   PLATFORM=PLATFORM_DESKTOP
--   GRAPHICS=GRAPHICS_API_OPENGL_33
-- Configuring done
CMake Error at libultraship/extern/CMakeLists.txt:73 (target_link_libraries):
  Target "ImGui" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



CMake Error at soh/CMakeLists.txt:2100 (target_link_libraries):
  Target "soh" links to:

    SDL2::SDL2

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.

no problem this is easy enough for me to test, honestly i attempted to get it working my self for awhile but i'm just not used to cmake like i am other build systems

[leggettc18]

It looks like you changed line 2063, that should stay at just find_package(SDL2), line 2069 is the one you needed to change. We're still finding the same package but then linking a different library from that package. Like this:

 find_package(SDL2)
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 set(ADDITIONAL_LIBRARY_DEPENDENCIES
     "libultraship;"
     "ZAPDUtils;"
     SDL2::SDL2-static #change this line
     "$<$<BOOL:${BUILD_CROWD_CONTROL}>:SDL2_net::SDL2_net>"
     ${CMAKE_DL_LIBS}
     Threads::Threads
)