The 'critical' tags are specs that either hang or cause a segfault. These can be listed with 'mspec tag --list critical'. The rest of the tags are from a variety of issues. These are not necessarily bugs in 1.9. Most are probably specs that need to be fixed to be compatible with both 1.8 and 1.9. The tags do not block syntax errors since those occur while the file is loading.
…ing a scope.
…ence. See http://jira.codehaus.org/browse/JRUBY-3328 for further info.