cross-x86_64-linux-musl: no need to build it on x86_64-musl.

srcpkgs/cross-x86_64-linux-musl/template

@@ -32,6 +32,11 @@ makedepends="libfl-devel zlib-devel gmp-devel mpfr-devel libmpc-devel"
 nostrip_files="libgcc.a libgcov.a libgcc_eh.a"
 depends="${pkgname}-libc-${version}_${revision}"
 
+if [ "$XBPS_TARGET_MACHINE" = "x86_64-musl" ]; then
+	# No need to build a cross compiler if we are running x86_64-musl.
+	msg_normal "${pkgname}-${version}: cannot be built on $XBPS_TARGET_MACHINE\n"
+	exit 0
+fi
 _apply_patch() {
 	local pname="$(basename $1)"