$ git clone -n https://src.fedoraproject.org/rpms/ghc-extra.git /var/lib/mock/f41-build-837900-159471/root/chroot_tmpdir/scmroot/ghc-extra
Cloning into '/var/lib/mock/f41-build-837900-159471/root/chroot_tmpdir/scmroot/ghc-extra'...
$ git fetch origin 1179c896998dc05bf437d50997ee8fa2c0c2dc02:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-extra
 * [new ref]         1179c896998dc05bf437d50997ee8fa2c0c2dc02 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1179c89 https://hackage.haskell.org/package/extra-1.7.16/changelog