It is underdocumented, but you don’t have to go out of your way because you in most cases you can use prepackaged toolchains that other people have made. I hav

It is underdocumented, but you don’t have to go out of your way because you in most cases you can use prepackaged toolchains that other people have made. I have successfully written my own toolchain rules in Bazel. Yes, it is a pain. But it’s usually only necessary if you have some kind of unusual target—usually, someone else has written the toolchain rules for you. I've even witnessed a Bazel build system that made working DOS binaries. The entire set of rules was smaller than you might think.