$ git clone -n https://src.fedoraproject.org/rpms/glib2.git /var/lib/mock/f42-build-864506-172356/root/chroot_tmpdir/scmroot/glib2
Cloning into '/var/lib/mock/f42-build-864506-172356/root/chroot_tmpdir/scmroot/glib2'...
$ git fetch origin 7b0d00dfe8a96fbe6fa5bff8eda4b9bc918f9d03:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/glib2
 * [new ref]         7b0d00dfe8a96fbe6fa5bff8eda4b9bc918f9d03 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7b0d00d Drop ifuncs to unbreak qemu-user-static binaries