Expand try block a bit to catch more exceptions. (#737)

Author: tetron

cwltool/main.py

@@ -458,14 +458,10 @@ def main(argsl=None,  # type: List[str]
                                                                         fetcher_constructor,
                                                                         overrides,
                                                                         tool_file_uri)
-        except Exception as e:
-            _logger.error(Text(e), exc_info=args.debug)
-            return 1
 
-        if args.overrides:
-            overrides.extend(load_overrides(file_uri(os.path.abspath(args.overrides)), tool_file_uri))
+            if args.overrides:
+                overrides.extend(load_overrides(file_uri(os.path.abspath(args.overrides)), tool_file_uri))
 
-        try:
             document_loader, workflowobj, uri = fetch_document(uri, resolver=resolver,
                                                                fetcher_constructor=fetcher_constructor)