Don't import theano before calling nose.main()

bin/theano-nose

@@ -20,6 +20,7 @@ import logging
 _logger = logging.getLogger('theano.bin.theano-nose')
 _logger.setLevel(logging.WARN)
 
+import os
 import nose
 import textwrap
 import sys
@@ -32,12 +33,18 @@ def main():
         import theano
         sys.argv[i] = theano.__path__[0]
 
-    # Many Theano tests suppose device=cpu.
-    # I don't know how to do this tests only if we use theano-nose on Theano tests.
-    # So I make the try..except in case the script get reused elsewhere.
+    # Many Theano tests suppose device=cpu, so we need to raise an
+    # error if device==gpu.
+    # I don't know how to do this check only if we use theano-nose on
+    # Theano tests.  So I make an try..except in case the script get
+    # reused elsewhere.
+    # We should not import theano before call nose.main()
+    # As this cause import problem with nosetests.
+    # Should we find a way to don't modify sys.path?
+    if not os.path.exists('theano/__init__.py'):
         try:
-        import theano
-        if theano.config.device != "cpu":
+            from theano import config
+            if config.device != "cpu":
                 raise ValueError("Theano tests must be run with device=cpu."
                                  " This will also run GPU tests when possible.")
         except ImportError: