Fixed SyntaxError when installing via Python 3

NEWS

@@ -21,6 +21,9 @@ Improvements
   create a synthetic test recording any such exception.
   (Robert Collins, #1130429)
 
+* Fixed SyntaxError raised in ``_compat2x.py`` when installing via Python 3.
+  (Will Bond, #941958)
+
 * New class ``StreamResult`` which defines the API for the new result type.
   (Robert Collins)
 

setup.py

@@ -2,8 +2,10 @@
 """Distutils installer for testtools."""
 
 from setuptools import setup
+from distutils.command.build_py import build_py
 import email
 import os
+import sys
 
 import testtools
 cmd_class = {}
@@ -11,6 +13,14 @@ if getattr(testtools, 'TestCommand', None) is not None:
     cmd_class['test'] = testtools.TestCommand
 
 
+class testtools_build_py(build_py):
+    def build_module(self, module, module_file, package):
+        if sys.version_info >= (3,) and module == '_compat2x':
+            return
+        return build_py.build_module(self, module, module_file, package)
+cmd_class['build_py'] = testtools_build_py
+
+
 def get_version_from_pkg_info():
     """Get the version from PKG-INFO file if we can."""
     pkg_info_path = os.path.join(os.path.dirname(__file__), 'PKG-INFO')

testtools/compat.py

@@ -35,7 +35,7 @@ StringIO = try_imports(['StringIO.StringIO', 'io.StringIO'])
 
 try:
     from testtools import _compat2x as _compat
-except SyntaxError:
+except (SyntaxError, ImportError):
     from testtools import _compat3x as _compat
 
 reraise = _compat.reraise