[package] SDL2/2.28.5: Emscripten: Imported target "SDL2::SDL2-static" includes non-existent path

[skhaz]

Description

Since today I am getting the following error when compiling with emsdk. Before it worked fine.

CMake Error in CMakeLists.txt:
  Imported target "SDL2::SDL2-static" includes non-existent path

    "/home/runner/.conan2/p/emsdke60e2b9a46b66/p/bin/upstream/emscripten/cache/sysroot/include/SDL2"

It doesn't compile on my machine or in the GitHub Action.

include(default)

[settings]
arch=wasm
os=Emscripten

[tool_requires]
*: emsdk/3.1.48

Other profiles works well, like Windows, macOS e Ubuntu.

Steps to reproduce

Create a project which uses SDL2 and then compile it with emsdk.

Logs

Run cmake .. -DCMAKE_TOOLCHAIN_FILE="conan_toolchain.cmake" -DCMAKE_BUILD_TYPE=Release
-- Using Conan toolchain: /home/runner/work/carimbo/carimbo/build/conan_toolchain.cmake
-- Conan toolchain: C++ Standard 20 with extensions OFF
-- Conan: Target declared 'avif'
-- Conan: Target declared 'libaom-av1::libaom-av1'
-- Conan: Target declared 'libyuv::libyuv'
-- Conan: Target declared 'JPEG::JPEG'
-- Conan: Target declared 'dav1d::dav1d'
-- Conan: Component target declared 'WebP::webpdecoder'
-- Conan: Component target declared 'WebP::sharpyuv'
-- Conan: Component target declared 'WebP::webp'
-- Conan: Component target declared 'WebP::webpdemux'
-- Conan: Component target declared 'WebP::libwebpmux'
-- Conan: Target declared 'libwebp::libwebp'
-- Conan: Component target declared 'CURL::libcurl'
-- Conan: Component target declared 'OpenSSL::Crypto'
-- Conan: Component target declared 'OpenSSL::SSL'
-- Conan: Target declared 'openssl::openssl'
-- Conan: Target declared 'ZLIB::ZLIB'
-- Conan: Including build module from '/home/runner/.conan2/p/b/openscfce26254335e/p/lib/cmake/conan-official-openssl-variables.cmake'
-- Conan: Component target declared 'fmt::fmt'
-- Conan: Component target declared 'Ogg::ogg'
-- Conan: Target declared 'physfs-static'
-- Conan: Target declared 'sol2::sol2'
-- Conan: Target declared 'lua::lua'
-- Conan: Component target declared 'Vorbis::vorbis'
-- Conan: Component target declared 'Vorbis::vorbisenc'
-- Conan: Component target declared 'Vorbis::vorbisfile'
-- Conan: Component target declared 'vorbis::vorbisenc-alias'
-- Conan: Component target declared 'vorbis::vorbisfile-alias'
-- Conan: Target declared 'vorbis::vorbis'
-- Configuring done (5.0s)
CMake Error in CMakeLists.txt:
  Imported target "SDL2::SDL2-static" includes non-existent path

    "/home/runner/.conan2/p/emsdke60e2b9a46b66/p/bin/upstream/emscripten/cache/sysroot/include/SDL2"

  in its INTERFACE_INCLUDE_DIRECTORIES.  Possible reasons include:

  * The path was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and references files it does not
  provide.

-- Generating done (0.0s)
CMake Generate step failed.  Build files cannot be regenerated correctly.
Error: Process completed with exit code 1.

[SpaceIm]

It's weird. It could be a regression of conan 2.0.14 (released today). It's like if CMakeDeps was mixing up relative path defined by cpp_info.includedirs of sdl recipe with a sysroot path defined in cmake toolchain file of emsdk recipe (this sysroot path is also appended to CMAKE_FIND_ROOT_PATH by the same toolchain, there might be some tricky side effects with CMakeDeps).

[skhaz]

@SpaceIm, just to emphasize, this occurs only on the profile using the emsdk (locally, macOS host, or in CI, Ubuntu); I have CI running on the three main platforms and they have not been affected.

[skhaz]

@SpaceIm, I don't believe it's a regression; I tested with some previous versions up to 2.0.12, which is when I started using it.

Unless it's something in the SDL2 package or in the Conan backend.

Is there any way to perform a rollback besides downgrading the package installed via pip?

[skhaz]

I downgraded Conan to version 2.0.11 and SDL2 to version 2.28.2, and the same error persists. So I don't know what it could be.

[skhaz]

@SpaceIm, I discovered the issue; it actually occurs in recent versions of the EMSDK. By downgrading to an earlier version, the problem does not occur.

Working version for SDL2 emsdk/3.1.44

Closing.

[SpaceIm]

The problem of emsdk I think is that it also contains pre-build binaries of libraries like sdl, and headers of SDL are in a different folder. Maybe we should remove these pre-build binaries from sysroot of emsdk during packaging.

[skhaz]

@SpaceIm, I raised the issue on the emsdk repository, a project collaborator said that emsdk should be built with the -sUSE_SDL=2 flag. I believe that at some point Conan removed this. If so, is there a way to enable this flag?

Thank you.

Reference: https://github.com/emscripten-core/emsdk/issues/1301#issuecomment-1814850196

[SpaceIm]

Actually we don't want SDL2 in emsdk recipe, because it would collide with SDL2 package from conan.

Just for reference, here is the content of bin/upstream/emscripten/system in emsdk/3.1.48 on macOS x86_64, and I see SDL2 headers (but no lib), it might be a problem for us:

$ ls /Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/*/*

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl-config
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl-config.bat
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl-config.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl2-config
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl2-config.bat
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/bin/sdl2-config.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/emscripten.h
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/wasm_simd128.h
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/README.md
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/al.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/asan_js.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/dlmalloc.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/emmalloc.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/jsmath.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/push_llvm_changes.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/push_musl_changes.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/stb_image.c
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/update_compiler_rt.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/update_libcxx.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/update_libcxxabi.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/update_libunwind.py
/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/update_musl.py

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/AL:
al.h    alc.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/EGL:
egl.h       eglext.h    eglplatform.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/GL:
freeglut_std.h  gl.h        glew.h      glext.h     glfw.h      glu.h       glut.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/GLES:
gl.h        glext.h     glplatform.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/GLES2:
gl2.h       gl2ext.h    gl2platform.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/GLES3:
gl2ext.h    gl3.h       gl31.h      gl32.h      gl3platform.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/GLFW:
glfw3.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/KHR:
khrplatform.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/SDL:
COPYING         SDL_config.h.in     SDL_config_wiz.h    SDL_hints.h     SDL_mixer.h     SDL_power.h     SDL_stdinc.h        SDL_video.h
SDL.h           SDL_config_android.h    SDL_copying.h       SDL_image.h     SDL_mouse.h     SDL_quit.h      SDL_surface.h       begin_code.h
SDL_assert.h        SDL_config_emscripten.h SDL_cpuinfo.h       SDL_input.h     SDL_mutex.h     SDL_rect.h      SDL_syswm.h     close_code.h
SDL_atomic.h        SDL_config_iphoneos.h   SDL_endian.h        SDL_joystick.h      SDL_name.h      SDL_render.h        SDL_thread.h
SDL_audio.h     SDL_config_macosx.h SDL_error.h     SDL_keyboard.h      SDL_opengl.h        SDL_revision.h      SDL_timer.h
SDL_blendmode.h     SDL_config_minimal.h    SDL_events.h        SDL_keycode.h       SDL_opengles.h      SDL_rotozoom.h      SDL_touch.h
SDL_clipboard.h     SDL_config_nintendods.h SDL_gesture.h       SDL_loadso.h        SDL_opengles2.h     SDL_rwops.h     SDL_ttf.h
SDL_compat.h        SDL_config_pandora.h    SDL_gfxPrimitives.h SDL_log.h       SDL_pixels.h        SDL_scancode.h      SDL_types.h
SDL_config.h        SDL_config_windows.h    SDL_haptic.h        SDL_main.h      SDL_platform.h      SDL_shape.h     SDL_version.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/X11:
X.h     Xatom.h     Xfuncs.h    XlibConf.h  Xmd.h       Xproto.h    Xutil.h     extensions  keysymdef.h
XKBlib.h    Xfuncproto.h    Xlib.h      Xlibint.h   Xosdefs.h   Xprotostr.h cursorfont.h    keysym.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/compat:
arm_neon.h  ctype.h     immintrin.h math.h      nmmintrin.h smmintrin.h stdlib.h    sys     tmmintrin.h wctype.h    xmmintrin.h
avxintrin.h emmintrin.h malloc.h    netdb.h     pmmintrin.h stdarg.h    string.h    time.h      wchar.h     xlocale.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/emscripten:
atomic.h        em_js.h         emscripten.h        heap.h          posix_socket.h      threading_legacy.h  wasmfs.h
bind.h          em_macros.h     eventloop.h     html5.h         promise.h       trace.h         webaudio.h
console.h       em_math.h       exports.h       html5_webgl.h       proxying.h      val.h           websocket.h
dom_pk_codes.h      em_types.h      fetch.h         html5_webgpu.h      stack.h         version.h       wget.h
em_asm.h        emmalloc.h      fiber.h         key_codes.h     threading.h     wasm_worker.h       wire.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/fakesdl:
SDL.h           SDL_config.h        SDL_gfxPrimitives.h SDL_keycode.h       SDL_name.h      SDL_quit.h      SDL_shape.h     SDL_ttf.h
SDL_assert.h        SDL_copying.h       SDL_haptic.h        SDL_loadso.h        SDL_opengl.h        SDL_rect.h      SDL_stdinc.h        SDL_types.h
SDL_atomic.h        SDL_cpuinfo.h       SDL_hints.h     SDL_log.h       SDL_opengles.h      SDL_render.h        SDL_surface.h       SDL_version.h
SDL_audio.h     SDL_endian.h        SDL_image.h     SDL_main.h      SDL_opengles2.h     SDL_revision.h      SDL_syswm.h     SDL_video.h
SDL_blendmode.h     SDL_error.h     SDL_input.h     SDL_mixer.h     SDL_pixels.h        SDL_rotozoom.h      SDL_thread.h
SDL_clipboard.h     SDL_events.h        SDL_joystick.h      SDL_mouse.h     SDL_platform.h      SDL_rwops.h     SDL_timer.h
SDL_compat.h        SDL_gesture.h       SDL_keyboard.h      SDL_mutex.h     SDL_power.h     SDL_scancode.h      SDL_touch.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/uuid:
uuid.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/wasi:
api.h       wasi-helpers.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/webgl:
webgl1.h    webgl1_ext.h    webgl2.h    webgl2_ext.h    webgl_api.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/include/webgpu:
README.md   webgpu.h    webgpu_cpp.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/cmake:
SDL2

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/compiler-rt:
CREDITS.TXT         __trap.c            emscripten_setjmp.c     include             readme.txt          stack_ops.S
LICENSE.TXT         emscripten_exception_builtins.c emscripten_tempret.s        lib             stack_limits.S

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/embind:
bind.cpp

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/fetch:
emscripten_fetch.c

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/gl:
gl.c            libprocaddr.c       webgl1.c        webgl2.c        webgl_internal.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/html5:
callback.c      dom_pk_codes.c      emscripten_wget.c   key_codes.c     offscreencanvas.c

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/libc:
README.md           dynlink.c           emscripten_memcpy.c     emscripten_scan_stack.c     pthread_sigmask.c       wasi-helpers.c
atexit_dummy.c          emscripten_console.c        emscripten_memcpy_bulkmem.S emscripten_syscall_stubs.c  raise.c
compat              emscripten_fiber.c      emscripten_memmove.c        emscripten_time.c       sbrk.c
crt1.c              emscripten_get_heap_size.c  emscripten_memset.c     kill.c              sigaction.c
crt1_proxy_main.c       emscripten_internal.h       emscripten_memset_bulkmem.S mktime.c            sigtimedwait.c
crt1_reactor.c          emscripten_libc_stubs.c     emscripten_mmap.c       musl                tzset.c

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/libcxx:
CREDITS.TXT LICENSE.TXT include     readme.txt  src

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/libcxxabi:
CREDITS.TXT LICENSE.TXT include     readme.txt  src

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/libunwind:
LICENSE.TXT include     readme.txt  src

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/pkgconfig:
egl.pc      glesv2.pc   glfw3.pc    sdl.pc

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/pthread:
em_task_queue.c         emscripten_thread_init.c    library_pthread.c       proxying_stub.c         thread_mailbox.c
em_task_queue.h         emscripten_thread_state.S   library_pthread_stub.c      pthread_create.c        thread_mailbox.h
emscripten_futex_wait.c     emscripten_tls_init.c       proxying.c          pthread_kill.c          thread_profiler.c
emscripten_futex_wake.c     emscripten_yield.c      proxying_legacy.c       pthread_self_stub.c     threading_internal.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/standalone:
__main_void.c       standalone.c        standalone_wasm_stdio.c

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/wasm_worker:
library_wasm_worker.c       library_wasm_worker_stub.c

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/wasmfs:
backend.h           file_table.cpp          memory_backend.h        proxied_async_js_impl_backend.h syscalls.cpp            wasmfs_internal.h
backends            file_table.h            no_fs.c             special_files.cpp       thread_utils.h
emscripten.cpp          fuzzer              paths.cpp           special_files.h         virtual.h
file.cpp            js_api.cpp          paths.h             support.cpp         wasmfs.cpp
file.h              js_impl_backend.h       pipe_backend.h          support.h           wasmfs.h

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/webgpu:
README.md   webgpu_cpp.cpp

/Users/spaceim/.conan2/p/b/emsdkf06e877bfd6a1/p/bin/upstream/emscripten/system/lib/websocket:
websocket_to_posix_socket.c

[skhaz]

@SpaceIm, I understand, that makes sense. But how do I enable SDL2 in emsdk for a WebAssembly build? It used to work without needing to change anything and it's broken now.

[SpaceIm]

Well, we have to understand why CMakeDeps tries to look into emsdk sysroot instead of conan cache for sdl discovery, and I think it can be reported to conan client. I don't have more time to investigate.

If you could share the diff between emsdk/3.1.44 & emsdk/3.1.48 packages on the same plaform, it could help:

diff of files list in bin/upstream/emscripten/system diff of bin/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake

[skhaz]

@SpaceIm, sure thing, I will look into that, I thought it was a known cause.

[SpaceIm]

There is a sdl2-config.cmake in bin/.emscripten_cache/sysroot/lib/cmake/SDL2/ (bin/.emscripten_cache/sysroot is the sysroot of emsdk, it's defined in its toolchain and even added to CMAKE_FIND_ROOT_PATH, so anything under this folder has precedence for find_package, find_library, find_path etc over anything else generated by CMakeDeps).

I think that this file is found during your CMake configuration, and also the one from CMakeDeps generated by conan, so it breaks because this sdl2-config.cmake defines SDL2_INCLUDE_DIRS so I guess it corrupts logic of SDL2Config.cmake generated by CMakeDeps:

set(SDL2_INCLUDE_DIRS "${EMSCRIPTEN_SYSROOT}/include/SDL2")
set(SDL2_LIBRARIES "-sUSE_SDL=2")

if(NOT TARGET SDL2::SDL2)
  add_library(SDL2::SDL2 INTERFACE IMPORTED)
  set_target_properties(SDL2::SDL2 PROPERTIES
    INTERFACE_COMPILE_OPTIONS "-sUSE_SDL=2"
    INTERFACE_LINK_LIBRARIES "-sUSE_SDL=2")

  add_library(SDL2::SDL2-static INTERFACE IMPORTED)
  set_target_properties(SDL2::SDL2-static PROPERTIES
    INTERFACE_COMPILE_OPTIONS "-sUSE_SDL=2"
    INTERFACE_LINK_LIBRARIES "-sUSE_SDL=2")

  add_library(SDL2::SDL2main INTERFACE IMPORTED)
endif()

Why does it work for you with 3.1.44 and not 3.1.48? I don't know, I don't see any significant difference.

I think that emsdk recipe should remove several files in emsdk packages (files related to SDL2, glfw, and stb for example: headers, libs, source file, cmake file and pkgconfig files), the risk is too high that things can collide with CMakeDeps or libs from conan cache.

[skhaz]

The defect appeared starting from version 3.1.45. Version 3.1.44 was the last one that worked.

[sykhro]

The issue persists. Also, it doesn't look like include directories are populated correctly, as consumers can't find emscripten.h out of the box

[skhaz]

@sykhro, please see my last comment.

[sykhro]

@sykhro, please see my last comment.

I saw that. I unfortunately need 3.1.50