$ git clone -n https://src.fedoraproject.org/rpms/maven-mapping.git /var/lib/mock/f41-build-712950-13044/root/chroot_tmpdir/scmroot/maven-mapping
Cloning into '/var/lib/mock/f41-build-712950-13044/root/chroot_tmpdir/scmroot/maven-mapping'...
$ git fetch origin 78485191ebd3f7471811e1d5818d71349f78b903:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/maven-mapping
 * [new ref]         78485191ebd3f7471811e1d5818d71349f78b903 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7848519 Set maven java source and target to 1.8, closes rhbz#2266671