$ git clone -n https://src.fedoraproject.org/rpms/rust-crypto-bigint0.2.git /var/lib/mock/f38-build-side-42-init-devel-1082939-29857/root/chroot_tmpdir/scmroot/rust-crypto-bigint0.2
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1082939-29857/root/chroot_tmpdir/scmroot/rust-crypto-bigint0.2'...
$ git fetch origin 21cebd93498492e0dcf9f6789ff9c07430fa4791:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crypto-bigint0.2
 * [new ref]         21cebd93498492e0dcf9f6789ff9c07430fa4791 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21cebd9 Initial import (crypto-bigint 0.2 compat package)