When a linter fails, it seems that we swallow the stack trace somewhere. As a result, it's difficult to work out how to fix my custom linter.
```
[2015-05-11 06:49:03] EXCEPTION: (PhutilAggregateException) Some linters failed:
- CustomPHPLinter: Exception: Unexpected node during static evaluation, of type: n_VARIABLE at [<arcanist>/src/lint/engine/ArcanistLintEngine.php:374]
arcanist(), flarc(), phutil()
#0 ArcanistLintEngine::run() called at [<arcanist>/src/workflow/ArcanistLintWorkflow.php:320]
#1 ArcanistLintWorkflow::run() called at [<arcanist>/scripts/arcanist.php:378]
```