Cannot open shared object libwgpu_native.so

[ghost]

Many of the examples include "./build/App" for Linux (and MacOS) as a way to start the application, but it doesn't work with relative path, you have to cd into the build folder and then execute ./App, to work as expected.

[eliemichel]

Okey this means there is a problem with the RPATH set in CMake, I have to investigate this.

[eliemichel]

Could you try again now on linux?

And could you test mac if that's easy for you? I did not fix it because I couldn't test; try maybe this in CMakeLists.txt:

elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")

    set(WGPU_RUNTIME_LIB ${WGPU}/bin/macos-${ARCH}/libwgpu_native.dylib)
    set_target_properties(
        webgpu
        PROPERTIES
            IMPORTED_LOCATION "libwgpu_native.dylib"  # change here
            INTERFACE_INCLUDE_DIRECTORIES "${WGPU}/include"
    )

else()

# [...]

# In target_copy_webgpu_binaries function:
if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
    set_target_properties(${Target} PROPERTIES INSTALL_RPATH "$ORIGIN/")
    set_target_properties(${Target} PROPERTIES BUILD_WITH_INSTALL_RPATH ON)
elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
    set_target_properties(${Target} PROPERTIES INSTALL_RPATH "@executable_path/")  # change here
    set_target_properties(${Target} PROPERTIES BUILD_WITH_INSTALL_RPATH ON)  # change here
    # remove what's left here
endif()

[eliemichel]

Not solving the issue... This seems like a CMake-side problem actually TBH: the generated executable tries to link _deps/.../libwgpu_native.so and at the same time sets the RPATH to /full/path/to/_deps/.../. It should do only one of the two, i.e. keep the rpath this way but with link to libwgpu_native.so without a path prefix.

Dynamic section at offset 0x4e6c8 contains 35 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libdl.so.2]
 0x0000000000000001 (NEEDED)             Shared library: [libX11.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libpthread.so.0]
 0x0000000000000001 (NEEDED)             Shared library: [_deps/webgpu-backend-wgpu-src/bin/linux-x86_64/libwgpu_native.so]
 0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000001d (RUNPATH)            Library runpath: [/mnt/g/SourceCode/LearnWebGPU-Code-folded/build-wgpu-gcc/_deps/webgpu-backend-wgpu-src/bin/linux-x86_64]

[eliemichel]

All right, turning on the IMPORTED_NO_SONAME target option does the trick, and feels much cleaner. Not sure it would work with macOS though.

[ghost]

Weird, I just tried to run step005 and it worked. I saw that the last time the branch was modified was 2 weeks ago. Not sure what exactly changed, but now it works without any modifications.

I cannot check that on Mac though, only Linux.

[eliemichel]

The issue was not in the branch itself but in the CMakeLists of the WebGPU distribution it was fetching! That's what I updated on July 14, hence the fix.