$ git clone -n https://src.fedoraproject.org/rpms/ghc-blaze-builder.git /var/lib/mock/f41-build-side-1-2636467-26231/root/chroot_tmpdir/scmroot/ghc-blaze-builder
Cloning into '/var/lib/mock/f41-build-side-1-2636467-26231/root/chroot_tmpdir/scmroot/ghc-blaze-builder'...
$ git fetch origin 736915d30c4097307e637a9f999856ff48b605a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-blaze-builder
 * [new ref]         736915d30c4097307e637a9f999856ff48b605a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 736915d https://hackage.haskell.org/package/blaze-builder-0.4.2.3/changelog