$ git clone -n https://src.fedoraproject.org/rpms/golang-gopkg-tylerb-is-1.git /var/lib/mock/f41-build-1036602-18741/root/chroot_tmpdir/scmroot/golang-gopkg-tylerb-is-1
Cloning into '/var/lib/mock/f41-build-1036602-18741/root/chroot_tmpdir/scmroot/golang-gopkg-tylerb-is-1'...
$ git fetch origin d22618400fb5dfc532d33d2bcba0108afb4a128b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-gopkg-tylerb-is-1
 * [new ref]         d22618400fb5dfc532d33d2bcba0108afb4a128b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d226184 Fix FTBFS