I happened to have just done this the other day. This regex works for me. (Note bonus regexes! The value you want goes to "@badProjects".)

my @msgs = <LOG>;

foreach $msg(@msgs) {
    if ($msg =~ ": error") {
        $errors++;
    }
    if ($msg =~ ": warning") {
        $warnings++;
    }
    if (($msg =~ "error") and ($msg =~ "warning") and !($msg =~ "0 err
+or")) {
        $failures++;
        push @badProjects, $msg;
    }
    if ($msg =~ "0 error") {
        $success++;
        push @goodProjects, $msg;
    }
}
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