$ git clone -n https://src.fedoraproject.org/rpms/maven-mapping.git /var/lib/mock/f42-build-3355543-45025/root/chroot_tmpdir/scmroot/maven-mapping
Cloning into '/var/lib/mock/f42-build-3355543-45025/root/chroot_tmpdir/scmroot/maven-mapping'...
$ git fetch origin a598004fd2bf7de579e4bcbe1d04129a99970a91:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/maven-mapping
 * [new ref]         a598004fd2bf7de579e4bcbe1d04129a99970a91 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a598004 Fix maven compiler attributes, close rhbz#2340824