$ git clone -n https://src.fedoraproject.org/rpms/ghc-hosc.git /var/lib/mock/f40-build-2074961-49450/root/chroot_tmpdir/scmroot/ghc-hosc
Cloning into '/var/lib/mock/f40-build-2074961-49450/root/chroot_tmpdir/scmroot/ghc-hosc'...
$ git fetch origin 4f0589ce2458831156024f8e67964573096309a8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-hosc
 * [new ref]         4f0589ce2458831156024f8e67964573096309a8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4f0589c https://hackage.haskell.org/package/hosc-0.20/changelog