Use the requested log level when handling broken stdout pipe.

src/pip/_internal/cli/base_command.py

@@ -130,7 +130,7 @@ class Command(object):
         # Set verbosity so that it can be used elsewhere.
         self.verbosity = options.verbose - options.quiet
 
-        setup_logging(
+        level_number = setup_logging(
             verbosity=self.verbosity,
             no_color=options.no_color,
             user_log_file=options.log,
@@ -197,7 +197,7 @@ class Command(object):
             # Bypass our logger and write any remaining messages to stderr
             # because stdout no longer works.
             print('ERROR: Pipe to stdout was broken', file=sys.stderr)
-            if logger.getEffectiveLevel() <= logging.DEBUG:
+            if level_number <= logging.DEBUG:
                 traceback.print_exc(file=sys.stderr)
 
             return ERROR

src/pip/_internal/utils/logging.py

@@ -216,6 +216,8 @@ class MaxLevelFilter(logging.Filter):
 
 def setup_logging(verbosity, no_color, user_log_file):
     """Configures and sets up all of the logging
+
+    Returns the requested logging level, as its integer value.
     """
 
     # Determine the level to be logging at.
@@ -230,6 +232,8 @@ def setup_logging(verbosity, no_color, user_log_file):
     else:
         level = "INFO"
 
+    level_number = getattr(logging, level)
+
     # The "root" logger should match the "console" level *unless* we also need
     # to log to a user log file.
     include_user_log = user_log_file is not None
@@ -310,3 +314,5 @@ def setup_logging(verbosity, no_color, user_log_file):
             }
         },
     })
+
+    return level_number

tests/functional/test_broken_stdout.py

@@ -1,3 +1,4 @@
+import os
 import subprocess
 import sys
 
@@ -42,6 +43,23 @@ def test_broken_stdout_pipe(deprecated_python):
     assert returncode == _BROKEN_STDOUT_RETURN_CODE
 
 
+def test_broken_stdout_pipe__log_option(deprecated_python, tmpdir):
+    """
+    Test a broken pipe to stdout when --log is passed.
+    """
+    log_path = os.path.join(str(tmpdir), 'log.txt')
+    stderr, returncode = setup_broken_stdout_test(
+        ['pip', '--log', log_path, 'list'],
+        deprecated_python=deprecated_python,
+    )
+
+    # Check that no traceback occurs.
+    assert 'raise BrokenStdoutLoggingError()' not in stderr
+    assert stderr.count('Traceback') == 0
+
+    assert returncode == _BROKEN_STDOUT_RETURN_CODE
+
+
 def test_broken_stdout_pipe__verbose(deprecated_python):
     """
     Test a broken pipe to stdout with verbose logging enabled.