Without the change `pkgsMusl.pkgsStatic.buildPackages.binutils.bintools`
build fails as:
$ ln: failed to create symbolic link './include': File exists
This happens because both host and target are `x86_64-unknown-linux-musl`.
But `hostPlatform` differs from `targetPlatform` by `isStatic` value.
By `./configure`'s standard it's not yet a cross-compilation. The change
tries to move things around only when tuples change.
Sergei Trofimovich
d381e51fb5