Fix terminal width detection.

.pre-commit-config.yaml

@@ -4,7 +4,7 @@
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
     -   id: autopep8-wrapper
-        args: ['-i', '--ignore=E265,E309,E501', '-v']
+        args: ['-i', '--ignore=E265,E309,E501']
     -   id: check-json
     -   id: check-yaml
     -   id: debug-statements

pre_commit/output.py

@@ -1,6 +1,5 @@
 from __future__ import unicode_literals
 
-import os
 import subprocess
 import sys
 
@@ -11,7 +10,7 @@ from pre_commit import five
 # TODO: smell: import side-effects
 COLS = int(
     subprocess.Popen(
-        ['tput', 'cols'], stdout=subprocess.PIPE, stderr=open(os.devnull, 'w'),
+        ['tput', 'cols'], stdout=subprocess.PIPE,
     ).communicate()[0] or
     # Default in the case of no terminal
     80

tests/commands/install_uninstall_test.py

@@ -382,7 +382,10 @@ def test_installed_from_venv(tmpdir_factory):
         # Should still pick up the python from when we installed
         ret, output = _get_commit_output(
             tmpdir_factory,
-            env_base={'HOME': os.environ['HOME']},
+            env_base={
+                'HOME': os.environ['HOME'],
+                'TERM': os.environ.get('TERM', ''),
+            },
         )
         assert ret == 0
         assert NORMAL_PRE_COMMIT_RUN.match(output)