$ git clone -n https://src.fedoraproject.org/rpms/rust-crypto-bigint.git /var/lib/mock/f40-build-2081495-49765/root/chroot_tmpdir/scmroot/rust-crypto-bigint
Cloning into '/var/lib/mock/f40-build-2081495-49765/root/chroot_tmpdir/scmroot/rust-crypto-bigint'...
$ git fetch origin 806b798ce2db9efa1367f3bc9077748c2aae8a0c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crypto-bigint
 * [new ref]         806b798ce2db9efa1367f3bc9077748c2aae8a0c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 806b798 Update to version 0.5.5; Fixes RHBZ#2250485