[Zope3-dev] zope.configuration and ImportErrors

[Florent Guillaume]

Today it's very hard to debug ImportErrors raise inside modules  
referenced through a zcml directive, because the ImportError is  
swallowed an no traceback comes back to the user. Just a
   ConfigurationError: ('Invalid value for', 'class', "Couldn't  
import some.class, cannot import name somename")
which doesn't point anywhere useful.

I'd like to modify zope.configuration.config to something like:

         try:
             mod = __import__(mname, *_import_chickens)
         except ImportError, v:
+            if sys.exc_info()[2].tb_next is not None:
+                # ImportError was caused deeper
+                raise
             raise ConfigurationError, (
                 "Couldn't import %s, %s" % (mname, v)
                 ), sys.exc_info()[2]

Instead of the simpler code that was there (this nice trick is by  
PJE, and is used ).

Also I need to fix zope.configuration.xmlconfig, today it has a bare  
except:

         try:
             self.context.begin(name, data, info)
         except:
             if self.testing:
                 raise
             raise ZopeXMLConfigurationError, (
                 info, sys.exc_info()[0], sys.exc_info()[1]
                 ), sys.exc_info()[2]

Shouldn't it just catch ConfigurationError?

With both changes I get much nicer error report: just a traceback  
with the correct info.

Florent

-- 
Florent Guillaume, Nuxeo (Paris, France)   Director of R&D
+33 1 40 33 71 59   http://nuxeo.com   fg at nuxeo.com