Global leaks to signal error correctly for Mocha (#282).
Revert "Merge pull request #285 from merio/fix_issue_284"

This reverts commit 3c582710363b7b9c363ea28dd75c01fb59789987, reversing
changes made to 483a3667016d1910fdffa63540912c4c32e02bf1.
0.4.6