$ git clone -n https://src.fedoraproject.org/rpms/rust-flate2.git /var/lib/mock/f41-build-side-1-2954325-35544/root/chroot_tmpdir/scmroot/rust-flate2
Cloning into '/var/lib/mock/f41-build-side-1-2954325-35544/root/chroot_tmpdir/scmroot/rust-flate2'...
$ git fetch origin 2711f63a3d99ce475fa1e5b1a0380bf51d6cb4ca:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-flate2
 * [new ref]         2711f63a3d99ce475fa1e5b1a0380bf51d6cb4ca -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2711f63 Update to version 1.0.34; Fixes RHBZ#2314987