$ git clone -n https://src.fedoraproject.org/rpms/ghc-feed.git /var/lib/mock/f39-build-1712390-41228/root/chroot_tmpdir/scmroot/ghc-feed
Cloning into '/var/lib/mock/f39-build-1712390-41228/root/chroot_tmpdir/scmroot/ghc-feed'...
$ git fetch origin 54e933feaf4fbfb3afef9cae82699fbf3e050276:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-feed
 * [new ref]         54e933feaf4fbfb3afef9cae82699fbf3e050276 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 54e933f revised .cabal file