[resent to whole list for posterity] This was fixed last year in the master and release-11 branches; it will be fixed in the next point release (11.3 or 12.0), or you can just apply the patch to the source tree manually:
https://savannah.gnu.org/bugs/index.php?60505 https://git.savannah.gnu.org/cgit/mit-scheme.git/commit/?h=master&id=837bb3f1ca75f867e115bf3a195de2f78517dce1 https://git.savannah.gnu.org/cgit/mit-scheme.git/commit/?h=release-11&id=493bfe8f463ad8bf0d6bbbb257a993ed1a4beeee
