not all headers are installed for C API

[ognevny]

when built with MSYS2 toolchain, wasmtime/conf.h isn't installed, and (for example) tree-sitter compilation fails with

In file included from C:/msys64/clang64/include/wasmtime.h:182:
C:/msys64/clang64/include/wasi.h:12:10: fatal error: 'wasmtime/conf.h' file not found
   12 | #include <wasmtime/conf.h>
      |          ^~~~~~~~~~~~~~~~~

[alexcrichton]

Thanks for the report! The installation of the C API changed a few versions ago in Wasmtime to use cmake to install, and cmake should install the conf.h header file. If it's missing here then that means whatever is managing the C API probably isn't pulling in the latest version one way or another. There's been a few other PRs/issues for tree-sitter using a Rust dependency on the C API and getting that working too.

If you're interested in primarily packaging tree-sitter this might be a better issue to raise with them? They might be more familiar with the build system and packaging of tree sitter.

[ognevny]

I forgot to answer, but cmake doesn't install conf.h this just can't be issue from tree-sitter's side

[alexcrichton]

Would you be able to provide some steps for reproduction?

[ognevny]

download msys2
run makepkg-mingw -s for recipe

[ognevny]

but without the line, that install conf.h manually (https://github.com/msys2/MINGW-packages/blob/cb29d91491e2e202d66e0ffc5a1ff2ed068e8622/mingw-w64-wasmtime/PKGBUILD#L118)

[alexcrichton]

I ran these commands:

$ cmake -G Ninja -DCMAKE_INSTALL_PREFIX=`pwd`/target/c-api-install -DBUILD_SHARED_LIBS=OFF -S ./crates/c-api -B target/build-static
$ cmake --build target/build-static
$ DESTDIR=./target/c-api-install2 cmake --install target/build-static

to model what that script is doing

The --install step shows:

...
-- Installing: /home/alex/code/wasmtime/target/c-api-install/include/wasmtime/conf.h
-- Up-to-date: ./target/c-api-install2/home/alex/code/wasmtime/target/c-api-install/include
-- Installing: ./target/c-api-install2/home/alex/code/wasmtime/target/c-api-install/include/wasi.h
...

which shows that the conf.h is being installed, just to the wrong spot.

I think this has to do with the combination of DESTDIR and -DCMAKE_INSTALL_PREFIX and those being different. I fear though that I'm not knowledgable enough with CMake to know how best to solve this.

[ognevny]

I wonder can you switch to meson?