$ git clone -n https://src.fedoraproject.org/rpms/apache-commons-exec.git /var/lib/mock/f43-build-61013906-6587691/root/chroot_tmpdir/scmroot/apache-commons-exec
Cloning into '/var/lib/mock/f43-build-61013906-6587691/root/chroot_tmpdir/scmroot/apache-commons-exec'...
$ git fetch origin c6a60064e318b27fe3f447bc4a11cd978116c0c7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/apache-commons-exec
 * [new ref]         c6a60064e318b27fe3f447bc4a11cd978116c0c7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c6a6006 Update sources