$ git clone -n https://src.fedoraproject.org/forks/hursand/rpms/gdb.git /var/lib/mock/f42-build-3156417-40813/root/chroot_tmpdir/scmroot/gdb
Cloning into '/var/lib/mock/f42-build-3156417-40813/root/chroot_tmpdir/scmroot/gdb'...
$ git fetch origin 481a274448c6de143e034922521f0c7a17507f69:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/hursand/rpms/gdb
 * [new ref]         481a274448c6de143e034922521f0c7a17507f69 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 481a274 Update release