$ git clone -n https://src.fedoraproject.org/rpms/tigervnc.git /var/lib/mock/f42-build-886771-187831/root/chroot_tmpdir/scmroot/tigervnc
Cloning into '/var/lib/mock/f42-build-886771-187831/root/chroot_tmpdir/scmroot/tigervnc'...
$ git fetch origin 6fad1f8fb4580e58dc1997715276139892e6bc97:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/tigervnc
 * [new ref]         6fad1f8fb4580e58dc1997715276139892e6bc97 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6fad1f8 1.15.0