$ git clone -n https://src.fedoraproject.org/rpms/rust-hashbrown.git /var/lib/mock/f41-build-side-1-3098665-39333/root/chroot_tmpdir/scmroot/rust-hashbrown
Cloning into '/var/lib/mock/f41-build-side-1-3098665-39333/root/chroot_tmpdir/scmroot/rust-hashbrown'...
$ git fetch origin 7370f6f31b038d371ace51f3e34d5cb2cca50d7b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-hashbrown
 * [new ref]         7370f6f31b038d371ace51f3e34d5cb2cca50d7b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7370f6f Update to version 0.15.1; Fixes RHBZ#2323720