I think that bug may be fixed in jemalloc by now.
The version of jemalloc that the jemalloc-sys crate tracks is from two years ago.
I tried bumping jemalloc to latest master but that makes the jemalloc-sys build fail (trivially with a missing script but still).
Also there is this: https://github.com/gnzlbg/jemallocator/issues/136