Cross compile build failure

[Yuri6037]

When attempting to cross compile from aarch64-unknown-linux-gnu to x86_64-unknown-linux-musl this crate chooses a completely wrong compiler name: musl-gcc. The must-gcc compiler cannot be used to build x86_64 under an aarch64 machine.

Why is cc-rs not using RUSTC_LINKER in this case which points to a valid compiler/linker for the target platform?

[dot-asm]

In a way the question answers itself. I mean the answer to the "why" is obviously somebody asked the related "why" question before and came up with an answer that made sense in a specific situation:-) But on a serious note, a similar question was asked and even with a reference to musl. The suggestion was to scrap most of the mapping table, more specifically entries for targets that rely on cross-linker having to be specified (and as a result being passed as RUSTC_LINKER). As an alternative one can flip the priorities and use the table as a fallback. As opposed to using RUSTC_LINKER as fallback that is. (I also advocate for providing an interface to interrogate rustc for linker, so that we have something to work with in case RUSTC_LINKER is not set...)