Fix python 2.6

pre_commit/languages/node.py

@@ -1,8 +1,8 @@
 import contextlib
-import subprocess
 
 from pre_commit.languages import helpers
 from pre_commit.languages import python
+from pre_commit.prefixed_command_runner import CalledProcessError
 
 
 NODE_ENV = 'node_env'
@@ -38,7 +38,7 @@ def install_environment(repo_cmd_runner):
         # Try and use the system level node executable first
         try:
             python_env.run('nodeenv -n system {{prefix}}{0}'.format(NODE_ENV))
-        except subprocess.CalledProcessError:
+        except CalledProcessError:
             # TODO: log failure here
             # cleanup
             # TODO: local.path(NODE_ENV).delete()

pre_commit/prefixed_command_runner.py

@@ -4,6 +4,27 @@ import os.path
 import subprocess
 
 
+class CalledProcessError(RuntimeError):
+    def __init__(self, returncode, cmd, expected_returncode, output=None):
+        self.returncode = returncode
+        self.cmd = cmd
+        self.expected_returncode = expected_returncode
+        self.output = output
+
+    def __str__(self):
+        return (
+            'Command: {0!r}\n'
+            'Return code: {1}\n'
+            'Expected return code {2}\n',
+            'Output: {3!r}\n'.format(
+                self.cmd,
+                self.returncode,
+                self.expected_returncode,
+                self.output,
+            ),
+        )
+
+
 def _replace_cmd(cmd, **kwargs):
     return [part.format(**kwargs) for part in cmd]
 
@@ -40,8 +61,8 @@ class PrefixedCommandRunner(object):
         returncode = proc.returncode
 
         if retcode is not None and retcode != returncode:
-            raise subprocess.CalledProcessError(
-                returncode, replaced_cmd, output=(stdout, stderr),
+            raise CalledProcessError(
+                returncode, replaced_cmd, retcode, output=(stdout, stderr),
             )
 
         return proc.returncode, stdout, stderr

tests/prefixed_command_runner_test.py

@@ -6,6 +6,7 @@ import subprocess
 from plumbum import local
 
 from pre_commit.prefixed_command_runner import _replace_cmd
+from pre_commit.prefixed_command_runner import CalledProcessError
 from pre_commit.prefixed_command_runner import PrefixedCommandRunner
 
 
@@ -129,7 +130,7 @@ def test_exists_does_exist(tmpdir):
 
 def test_raises_on_error(popen_mock, makedirs_mock):
     popen_mock.return_value.returncode = 1
-    with pytest.raises(subprocess.CalledProcessError):
+    with pytest.raises(CalledProcessError):
         instance = PrefixedCommandRunner(
             '.', popen=popen_mock, makedirs=makedirs_mock,
         )