$ git clone -n https://src.fedoraproject.org/rpms/rust-unic-langid.git /var/lib/mock/f42-build-side-115233-61078246-6588738/root/chroot_tmpdir/scmroot/rust-unic-langid
Cloning into '/var/lib/mock/f42-build-side-115233-61078246-6588738/root/chroot_tmpdir/scmroot/rust-unic-langid'...
$ git fetch origin b3c28757390bcca2ee71488965f222ea6bae593f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-unic-langid
 * [new ref]         b3c28757390bcca2ee71488965f222ea6bae593f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b3c2875 Update to version 0.6.9; Fixes RHBZ#2365361