A file opened in 'b' mode needs bytes, not strings. Try to do this in a clean-ish way...

1 files changed, 2 insertions, 1 deletions

diff --git a/test/coveragetest.py b/test/coveragetest.py
index 694288f0..aad90e5c 100644
--- a/test/coveragetest.py
+++ b/test/coveragetest.py
@@ -4,6 +4,7 @@ import imp, os, random, shlex, shutil, sys, tempfile, textwrap
 
 import coverage
 from coverage.backward import sorted, StringIO      # pylint: disable=W0622
+from coverage.backward import to_bytes
 from backtest import run_command
 from backunittest import TestCase
 
@@ -147,7 +148,7 @@ class CoverageTest(TestCase):
         # Create the file.
         f = open(filename, 'wb')
         try:
-            f.write(text)
+            f.write(to_bytes(text))
         finally:
             f.close()