$ grep 'sort:.*+' -r success error |sort -u
error/ispell-ru-lebedev-0.99g4-alt1:sort: open failed: +1: No such file or directory
error/pdksh-1:5.2.14-alt1:sort: open failed: +2n: No such file or directory
success/ispell-1:3.2.06-alt7:sort: open failed: +1: No such file or directory
success/sqlite-2.8.16-alt1.1.0:sort: open failed: +4: No such file or directory
$