Hi Stéphane,
There was a new jbuilder release that fixes
#881770.
I've updated the package in alioth for the new release.
FYI, jbuilder is being renamed to dune, but the actually rename (e.g. the command name) has not happened yet. I'm not sure how Debian package rename is done so I left it named as jbuilder.
Would you review the change and upload?
Best regards,
Andy