$ git clone -n https://src.fedoraproject.org/rpms/rust-which.git /var/lib/mock/f39-build-1455881-32920/root/chroot_tmpdir/scmroot/rust-which
Cloning into '/var/lib/mock/f39-build-1455881-32920/root/chroot_tmpdir/scmroot/rust-which'...
$ git fetch origin 8eda07584e5094dd3dc90c363269f2530c134c4d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-which
 * [new ref]         8eda07584e5094dd3dc90c363269f2530c134c4d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8eda075 Update to version 4.4.2; Fixes RHBZ#2237164