To solve the problem in a robust way, the C library has to be part of the target. For example on Debian Linux, glibc is the native libc. On Alpine Linux, musl is the native libc. In LLVM terminology, this is the "C ABI environment" part of the "target triple".

If your compiler supports cross compiling, you might look into the strategies that Zig does[1]. If it only supports native builds, you probably want to detect the native libc. Again here it might be useful to look at what Zig does[2].

[1]: https://ziglang.org/download/0.4.0/release-notes.html#Zig-sh... [2]: https://ziglang.org/download/0.4.0/release-notes.html#Libc-D...