fixed #1141

pre_commit/error_handler.py

@@ -4,12 +4,14 @@ from __future__ import unicode_literals
 
 import contextlib
 import os.path
+import sys
 import traceback
 
 import six
 
 from pre_commit import five
 from pre_commit import output
+from pre_commit.constants import VERSION as pre_commit_version
 from pre_commit.store import Store
 
 
@@ -29,6 +31,9 @@ def _log_and_exit(msg, exc, formatted):
         five.to_bytes(msg), b': ',
         five.to_bytes(type(exc).__name__), b': ',
         _to_bytes(exc), b'\n',
+        _to_bytes('pre-commit.version={}\n'.format(pre_commit_version)),
+        _to_bytes('sys.version={}\n'.format(sys.version.replace('\n', ' '))),
+        _to_bytes('sys.executable={}\n'.format(sys.executable)),
     ))
     output.write(error_msg)
     store = Store()

tests/error_handler_test.py

@@ -104,17 +104,29 @@ def test_log_and_exit(cap_out, mock_store_dir):
 
     printed = cap_out.get()
     log_file = os.path.join(mock_store_dir, 'pre-commit.log')
-    assert printed == (
+    printed_lines = printed.split('\n')
-        'msg: FatalError: hai\n'
+    assert len(printed_lines) == 6, printed_lines
-        'Check the log at {}\n'.format(log_file)
+    assert printed_lines[0] == 'msg: FatalError: hai'
-    )
+    assert re.match(r'^pre-commit.version=\d+\.\d+\.\d+$', printed_lines[1])
+    assert printed_lines[2].startswith('sys.version=')
+    assert printed_lines[3].startswith('sys.executable=')
+    assert printed_lines[4] == 'Check the log at {}'.format(log_file)
+    assert printed_lines[5] == ''  # checks for \n at the end of last line
 
     assert os.path.exists(log_file)
     with io.open(log_file) as f:
-        assert f.read() == (
+        logged_lines = f.read().split('\n')
-            'msg: FatalError: hai\n'
+        assert len(logged_lines) == 6, logged_lines
-            "I'm a stacktrace\n"
+        assert logged_lines[0] == 'msg: FatalError: hai'
+        assert re.match(
+            r'^pre-commit.version=\d+\.\d+\.\d+$',
+            printed_lines[1],
         )
+        assert logged_lines[2].startswith('sys.version=')
+        assert logged_lines[3].startswith('sys.executable=')
+        assert logged_lines[4] == "I'm a stacktrace"
+        # checks for \n at the end of stack trace
+        assert printed_lines[5] == ''
 
 
 def test_error_handler_non_ascii_exception(mock_store_dir):
@@ -136,7 +148,7 @@ def test_error_handler_no_tty(tempdir_factory):
         pre_commit_home=pre_commit_home,
     )
     log_file = os.path.join(pre_commit_home, 'pre-commit.log')
-    assert output[1].replace('\r', '') == (
+    output_lines = output[1].replace('\r', '').split('\n')
-        'An unexpected error has occurred: ValueError: ☃\n'
+    assert output_lines[0] == 'An unexpected error has occurred: ValueError: ☃'
-        'Check the log at {}\n'.format(log_file)
+    assert output_lines[-2] == 'Check the log at {}'.format(log_file)
-    )
+    assert output_lines[-1] == ''  # checks for \n at the end of stack trace

tests/main_test.py

@@ -164,11 +164,14 @@ def test_expected_fatal_error_no_git_repo(in_tmpdir, cap_out, mock_store_dir):
     with pytest.raises(SystemExit):
         main.main([])
     log_file = os.path.join(mock_store_dir, 'pre-commit.log')
-    assert cap_out.get() == (
+    cap_out_lines = cap_out.get().split('\n')
+    assert (
+        cap_out_lines[0] ==
         'An error has occurred: FatalError: git failed. '
-        'Is it installed, and are you in a Git repository directory?\n'
+        'Is it installed, and are you in a Git repository directory?'
-        'Check the log at {}\n'.format(log_file)
     )
+    assert cap_out_lines[-2] == 'Check the log at {}'.format(log_file)
+    assert cap_out_lines[-1] == ''  # checks for \n at the end of error message
 
 
 def test_warning_on_tags_only(mock_commands, cap_out, mock_store_dir):