[PATCH] subversion: show the reason if bindings import failed

[anatoly techtonik]

# HG changeset patch
# User anatoly techtonik <techtonik at gmail.com>
# Date 1294489093 -7200
# Node ID 02f8a2e5b2482b64cf1746818d843ca67c7c24b0
# Parent  72a3f1056c7e8ed4d336a986e58ed95008d14480
subversion: show the reason if bindings import failed

This shows the following message in debug mode:
Subversin bindings import failed:
  ImportError: No module named _core

diff -r 72a3f1056c7e -r 02f8a2e5b248 hgext/convert/subversion.py
--- a/hgext/convert/subversion.py	Fri Jan 07 18:41:18 2011 +0200
+++ b/hgext/convert/subversion.py	Sat Jan 08 14:18:13 2011 +0200
@@ -22,6 +22,8 @@
 from common import NoRepo, MissingTool, commit, encodeargs, decodeargs
 from common import commandline, converter_source, converter_sink, mapfile
 
+bindings = True
+bindexception = None
 try:
     from svn.core import SubversionException, Pool
     import svn
@@ -35,7 +37,9 @@
             module='svn.core',
             category=DeprecationWarning)
 
-except ImportError:
+except ImportError, inst:
+    bindings = False
+    bindexception = inst
     pass
 
 class SvnPathNotFound(Exception):
@@ -210,9 +214,9 @@
             raise NoRepo(_("%s does not look like a Subversion repository")
                          % url)
 
-        try:
-            SubversionException
-        except NameError:
+        if not bindings:
+            ui.debug("Subversion bindings import failed:\n  %s: %s\n" % 
+                (bindexception.__class__.__name__, bindexception))
             raise MissingTool(_('Subversion python bindings could not be loaded'))
 
         try: