Read-only filesystem error using cc during build

[grovesNL]

Crate name: spirv_cross or crates depending on it (e.g. gfx-backend-dx12)
Build failure link: https://docs.rs/crate/gfx-backend-dx12/0.5.9/builds/281262
Additional details: When running cc from spirv_cross we get the following message:

[INFO] [stderr] running: "c++" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-fno-omit-frame-pointer" "-m64" "-Wall" "-Wextra" "-DSPIRV_CROSS_EXCEPTIONS_TO_ASSERTIONS" "-DSPIRV_CROSS_WRAPPER_NO_EXCEPTIONS" "-DSPIRV_CROSS_WRAPPER_GLSL" "-DSPIRV_CROSS_WRAPPER_HLSL" "-Fo/opt/rustwide/target/x86_64-pc-windows-msvc/debug/build/spirv_cross-f7ca93fa2885997b/out/src/wrapper.o" "-c" "src/wrapper.cpp"
[INFO] [stderr] cargo:warning=src/wrapper.cpp:2: warning: ignoring #pragma warning [-Wunknown-pragmas]
[INFO] [stderr] cargo:warning= 2 | #pragma warning(disable : 4996 4101)
[INFO] [stderr] cargo:warning= |
[INFO] [stderr] cargo:warning=Assembler messages:
[INFO] [stderr] cargo:warning=Fatal error: can't create wrapper.o: Read-only file system
[INFO] [stderr] exit code: 1
[INFO] [stderr]
[INFO] [stderr] --- stderr
[INFO] [stderr]
[INFO] [stderr]
[INFO] [stderr] error occurred: Command "c++" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-fno-omit-frame-pointer" "-m64" "-Wall" "-Wextra" "-DSPIRV_CROSS_EXCEPTIONS_TO_ASSERTIONS" "-DSPIRV_CROSS_WRAPPER_NO_EXCEPTIONS" "-DSPIRV_CROSS_WRAPPER_GLSL" "-DSPIRV_CROSS_WRAPPER_HLSL" "-Fo/opt/rustwide/target/x86_64-pc-windows-msvc/debug/build/spirv_cross-f7ca93fa2885997b/out/src/wrapper.o" "-c" "src/wrapper.cpp" with args "c++" did not execute successfully (status code exit code: 1).
[INFO] [stderr]
[INFO] [stderr]
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed

I'm not sure how to resolve this so I was wondering if I could get some help. I thought the path (/opt/rustwide/target/x86_64-pc-windows-msvc/debug/build/spirv_cross-f7ca93fa2885997b/out/src/wrapper.o) would be writable because it's inside of out.

The spirv_cross build script is a pretty typical cc setup and should use OUT_DIR from the environment: https://github.com/grovesNL/spirv_cross/blob/master/spirv_cross/build.rs

[Nemo157]

It looks like the -Fo argument is ignored, running cargo build --target x86_64-pc-windows-msvc results in a bunch of .o files appearing in the root directory when building spirv_cross-0.20.0.

[Nemo157]

(I think it's trying to pass MSVC flags to g++, that should be a -o flag).

[grovesNL]

Ah ok, that would make sense, thanks! cc-rs would've generated these flags so it's surprising we'd see MSVC flags if it detected that g++ is being used.

I guess the bigger issue is that we're trying to cross-compile a Windows-only crate, so we'd prefer to use a Windows host and require MSVC instead of g++. For gfx-backend-dx12, could we use Windows as the host to avoid cross-compilation, or require MSVC to be used through package metadata somehow?

[pietroalbini]

We don't have any Windows build hosts unfortunately :(

[jyn514]

Closing due to inactivity; feel free to reopen if you're still having trouble and have time to debug things.