cross-armv7l-linux-musleabihf: don't build on self

srcpkgs/cross-armv7l-linux-musleabihf/template

@@ -42,6 +42,10 @@ nostrip_files="libcaf_single.a libgcc.a libgcov.a libgcc_eh.a
  libgnarl_pic.a libgnarl.a libgnat_pic.a libgnat.a"
 depends="${pkgname}-libc-${version}_${revision}"
 
+if [ "$XBPS_TARGET_MACHINE" = "armv7l-musl" ]; then
+	broken="Can't build crosstoolchain to itself"
+fi
+
 _apply_patch() {
 	local args="$1" pname="$(basename $2)"