$ git clone -n https://src.fedoraproject.org/rpms/ghc-HsYAML.git /var/lib/mock/f41-build-839485-160201/root/chroot_tmpdir/scmroot/ghc-HsYAML
Cloning into '/var/lib/mock/f41-build-839485-160201/root/chroot_tmpdir/scmroot/ghc-HsYAML'...
$ git fetch origin 5ec2f1a285f7fc7022c6c49b5cc6cf47843a43fd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-HsYAML
 * [new ref]         5ec2f1a285f7fc7022c6c49b5cc6cf47843a43fd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5ec2f1a https://hackage.haskell.org/package/HsYAML-0.2.1.4/changelog