Cannot build the tree-sitter-python grammar using Rust x86_64-unknown-linux-musl target

[Luni-4]

I tried to build the tree-sitter-python project described here using the Rust x86_64-unknown-linux-musl target but it seems the compiler can't be found. Perhaps adding the .compiler("gcc") option here?

Thanks in advance for your help! :)

[maxbrunsfeld]

Do you have gcc and g++ on your PATH? It should find them if so.

[maxbrunsfeld]

Oh, I guess you need an executable called musl-c++?

I’m not very familiar with musl, so I’m not sure why the ‘cc’ crate is trying to invoke that tool.

[Luni-4]

Yay! 😄

I built tree-sitter-python locally adding compiler("gcc") to the build.rs file, now it works perfectly! It didn't affect the cargo build command either. Do you want a PR?

[maxbrunsfeld]

Hmm, I would prefer that it use the default compiler instead of hard-coding gcc. What if you just set the CC=gcc CXX=g++ environment variables when running cargo build?

[Luni-4]

It works the same! Thank you! Perhaps adding this to the README explaining how to build using musl?

[harrysarson]

So the issue here is the most straightforward way to get a musl compiler is apt install musl-tools (or pacman -Syu musl or whatever for redhat). These packages provide musl-gcc with a musl based libc.a. They do not provide musl-g++ nor a musl based libstdc++.a (no idea why not). This explains why the build.rs script cannot find musl-g++: it simply does not exist.

The only way I know of to get a musl-g++ executable is to compile it your self (not that hard if you use https://github.com/richfelker/musl-cross-make).

What if you just set the CC=gcc CXX=g++ environment variables when running cargo build?

This kind of works! It uses the system gcc and g++ to compiler the tree-sitter c/c++ files into static libraries and then musl-gcc to link everything (including those static libraries) together into a static executable. The possible problem is that there may (unlikely I think) be an ABI mismatch between the system gcc (that uses one libc/libstdc++) and (musl-gcc that uses a different libc/libstdc++`).

The musl website has the following to say about compiling c++ programs.

Be aware that, "out of the box", the wrapper only supports C applications, not C++. This is because the C++ libraries and headers are missing from the musl include/library path. The existing libstdc++ is actually compatible with musl in most cases and could be used by copying it into the musl library path, but the C++ header files are usually not compatible. One option may be rebuilding just libstdc++ against musl; however, if C++ support is needed, it's recommended just to build a native toolchain targetting musl.