$ git clone -n https://src.fedoraproject.org/rpms/xerces-c.git /var/lib/mock/f42-build-862894-171228/root/chroot_tmpdir/scmroot/xerces-c
Cloning into '/var/lib/mock/f42-build-862894-171228/root/chroot_tmpdir/scmroot/xerces-c'...
$ git fetch origin 93883973382e6427cb20f5e4f31163ba535fc610:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xerces-c
 * [new ref]         93883973382e6427cb20f5e4f31163ba535fc610 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9388397 Merge mingw32/64 package