diff -r d500ddae7494 -r 4b1af1c867fa mercurial/posix.py
--- a/mercurial/posix.py	Sun Nov 06 00:37:50 2016 -0700
+++ b/mercurial/posix.py	Thu Oct 20 21:38:44 2016 +0900
@@ -463,36 +463,6 @@
 def gethgcmd():
     return sys.argv[:1]
 
-def termwidth():
-    try:
-        import array
-        import termios
-        for dev in (sys.stderr, sys.stdout, sys.stdin):
-            try:
-                try:
-                    fd = dev.fileno()
-                except AttributeError:
-                    continue
-                if not os.isatty(fd):
-                    continue
-                try:
-                    arri = fcntl.ioctl(fd, termios.TIOCGWINSZ, '\0' * 8)
-                    width = array.array('h', arri)[1]
-                    if width > 0:
-                        return width
-                except AttributeError:
-                    pass
-            except ValueError:
-                pass
-            except IOError as e:
-                if e[0] == errno.EINVAL:
-                    pass
-                else:
-                    raise
-    except ImportError:
-        pass
-    return 80
-
 def makedir(path, notindexed):
     os.mkdir(path)