$ git clone -n https://src.fedoraproject.org/rpms/jemalloc.git /var/lib/mock/f41-build-side-1-2751202-31096/root/chroot_tmpdir/scmroot/jemalloc
Cloning into '/var/lib/mock/f41-build-side-1-2751202-31096/root/chroot_tmpdir/scmroot/jemalloc'...
$ git fetch origin 690d6a3a495290baba04e7a01e844a07c7105bd9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jemalloc
 * [new ref]         690d6a3a495290baba04e7a01e844a07c7105bd9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 690d6a3 Correct actual project URL (rhbz#2188965)