I've been having trouble getting dotnet programs to run when they rely on DllImport attributes. Here's a simple github repo that demonstrates the problem:
https://github.com/cwstra/nixos-dll-example/tree/example

On my nixos machine, running nix-shell run "dotnet run" in there spits out:

"Error loading unmanaged library from path: <snip>/nixos-dll-example/bin/Debug/net7.0/runtimes/linux-x64/native/libassimp.so".

From the path, I take it that it's not trying to import a globally-installed library (though I did add it to the nix-shell just in case). Does anyone have insight as to if/how I could set up an environment where I could work on projects with these dependencies?

In reply to @cwstra:matrix.org

I've been having trouble getting dotnet programs to run when they rely on DllImport attributes. Here's a simple github repo that demonstrates the problem:
https://github.com/cwstra/nixos-dll-example/tree/example

On my nixos machine, running nix-shell run "dotnet run" in there spits out:

"Error loading unmanaged library from path: <snip>/nixos-dll-example/bin/Debug/net7.0/runtimes/linux-x64/native/libassimp.so".

From the path, I take it that it's not trying to import a globally-installed library (though I did add it to the nix-shell just in case). Does anyone have insight as to if/how I could set up an environment where I could work on projects with these dependencies?

$ ldd bin/Debug/net7.0/runtimes/linux-x64/native/libassimp.so
        linux-vdso.so.1 (0x00007ffe88bd4000)
        libz.so.1 => not found
        librt.so.1 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/librt.so.1 (0x00007fd439b52000)
        libstdc++.so.6 => not found
        libm.so.6 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libm.so.6 (0x00007fd439a72000)
        libgcc_s.so.1 => /nix/store/jd99cyc0251p0i5y69w8mqjcai8mcq7h-xgcc-12.2.0-libgcc/lib/libgcc_s.so.1 (0x00007fd438bdf000)
        libc.so.6 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libc.so.6 (0x00007fd4389f9000)
        /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib64/ld-linux-x86-64.so.2 (0x00007fd439b59000)

The assimp native library depends on libz and libstdc++. Add this to the shellHook:

export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [ pkgs.stdenv.cc.libc pkgs.zlib ]}:$LD_LIBRARY_PATH

In reply to @raphi:tapesoftware.net

$ ldd bin/Debug/net7.0/runtimes/linux-x64/native/libassimp.so
        linux-vdso.so.1 (0x00007ffe88bd4000)
        libz.so.1 => not found
        librt.so.1 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/librt.so.1 (0x00007fd439b52000)
        libstdc++.so.6 => not found
        libm.so.6 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libm.so.6 (0x00007fd439a72000)
        libgcc_s.so.1 => /nix/store/jd99cyc0251p0i5y69w8mqjcai8mcq7h-xgcc-12.2.0-libgcc/lib/libgcc_s.so.1 (0x00007fd438bdf000)
        libc.so.6 => /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib/libc.so.6 (0x00007fd4389f9000)
        /nix/store/46m4xx889wlhsdj72j38fnlyyvvvvbyb-glibc-2.37-8/lib64/ld-linux-x86-64.so.2 (0x00007fd439b59000)

The assimp native library depends on libz and libstdc++. Add this to the shellHook:

export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [ pkgs.stdenv.cc.libc pkgs.zlib ]}:$LD_LIBRARY_PATH

build fails as such:

MatrixRoomUtils.Web-v1> unpacking sources
MatrixRoomUtils.Web-v1> unpacking source archive /nix/store/ghrc75bpl7lkzjfyg7y5mw04i5bw7kvm-h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source
MatrixRoomUtils.Web-v1> source root is h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source
MatrixRoomUtils.Web-v1> patching sources
MatrixRoomUtils.Web-v1> updateAutotoolsGnuConfigScriptsPhase
MatrixRoomUtils.Web-v1> configuring
MatrixRoomUtils.Web-v1> Executing dotnetConfigureHook
MatrixRoomUtils.Web-v1> Cannot find a manifest file.
MatrixRoomUtils.Web-v1> For a list of locations searched, specify the "-d" option before the tool name.
MatrixRoomUtils.Web-v1> No tools were restored.
MatrixRoomUtils.Web-v1>   Determining projects to restore...
MatrixRoomUtils.Web-v1> /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/MatrixRoomUtils.Web/MatrixRoomUtils.Web.csproj : error NU1101: Unable to find package Microsoft.NETCore.App.Runtime.Mono.browser-wasm. No packages exist with this id in source(s): nugetSource
MatrixRoomUtils.Web-v1>   Failed to restore /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/MatrixRoomUtils.Web/MatrixRoomUtils.Web.csproj (in 1.12 sec).
MatrixRoomUtils.Web-v1>   Restored /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/LibMatrix/LibMatrix/LibMatrix.csproj (in 538 ms).
error: builder for '/nix/store/mmjdifnfgrc3f4ragf8pql2fxsc73m1a-MatrixRoomUtils.Web-v1-1.drv' failed with exit code 1;

build fails as such:

...
MatrixRoomUtils.Web-v1>   Determining projects to restore...
MatrixRoomUtils.Web-v1> /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/MatrixRoomUtils.Web/MatrixRoomUtils.Web.csproj : error NU1101: Unable to find package Microsoft.NETCore.App.Runtime.Mono.browser-wasm. No packages exist with this id in source(s): nugetSource
MatrixRoomUtils.Web-v1>   Failed to restore /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/MatrixRoomUtils.Web/MatrixRoomUtils.Web.csproj (in 1.12 sec).
MatrixRoomUtils.Web-v1>   Restored /build/h6sn3kw7ld0rilnv6gf49qs01zsnhg34-source/LibMatrix/LibMatrix/LibMatrix.csproj (in 538 ms).
error: builder for '/nix/store/mmjdifnfgrc3f4ragf8pql2fxsc73m1a-MatrixRoomUtils.Web-v1-1.drv' failed with exit code 1;

In reply to @yarekt:matrix.org
Just out of curiosity, is it possible to convert this addition to be system wide? using environment.sessionVariables sort of doesn't look right. I have to compile and run a bunch of different dotnet projects, this lib is needed a lot. Wouldn't mind having it available system wide, or I'll basically be stuck in a nix-shell all the time