$ git clone -n https://src.fedoraproject.org/rpms/ghc-servant.git /var/lib/mock/f41-build-840185-160595/root/chroot_tmpdir/scmroot/ghc-servant
Cloning into '/var/lib/mock/f41-build-840185-160595/root/chroot_tmpdir/scmroot/ghc-servant'...
$ git fetch origin 846723bd843cfd461605fd5d3e35e217a4b5a1fe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-servant
 * [new ref]         846723bd843cfd461605fd5d3e35e217a4b5a1fe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 846723b https://hackage.haskell.org/package/servant-0.20.1/changelog