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This patch (surprisingly) seems to do the job quite nicely:
diff -r 1280b38fe583 Lib/test/test_os.py
--- a/Lib/test/test_os.py	Tue Oct 16 23:14:03 2012 +1000
+++ b/Lib/test/test_os.py	Tue Oct 16 21:25:36 2012 +0000
@@ -40,6 +40,20 @@
 or (st.st_mtime != st[8])
 or (st.st_ctime != st[9]))
 
+try:
+ import posix
+except ImportError:
+ # Windows has nanosecond utime resolution.
+ UTIME_EPSILON = 2e-9
+else:
+ import sysconfig
+ if 'HAVE_UTIMENSAT' in posix._have_functions:
+ UTIME_EPSILON = 2e-9
+ elif 'HAVE_UTIMES' in sysconfig.get_config_vars():
+ UTIME_EPSILON = 2e-6
+ else:
+ UTIME_EPSILON = 1.0
+
 # Detect whether we're on a Linux system that uses the (now outdated
 # and unmaintained) linuxthreads threading library. There's an issue
 # when combining linuxthreads with a failed execv call: see
@@ -312,18 +326,32 @@
 st0 = os.stat(filename)
 # Doesn't set anything new, but sets the time tuple way
 utime(filename, (attr(st0, "st_atime"), attr(st0, "st_mtime")))
- # Setting the time to the time you just read, then reading again,
- # should always return exactly the same times.
 st1 = os.stat(filename)
- self.assertEqual(attr(st0, "st_mtime"), attr(st1, "st_mtime"))
- self.assertEqual(attr(st0, "st_atime"), attr(st1, "st_atime"))
+
+ def _t(left, right, attr, name):
+ l = attr(left, name)
+ r = attr(right, name)
+ if isinstance(l, int):
+ assert isinstance(r, int)
+ l = l / 1e9
+ r = r / 1e9
+ return abs(l - r)
+
+ epsilon = UTIME_EPSILON
+ self.assertLess(_t(st0, st1, attr, "st_mtime"), epsilon)
+ self.assertLess(_t(st0, st1, attr, "st_atime"), epsilon)
+
 # Set to the current time in the old explicit way.
 os.utime(filename, None)
 st2 = os.stat(support.TESTFN)
 # Set to the current time in the new way
 os.utime(filename)
 st3 = os.stat(filename)
- self.assertAlmostEqual(attr(st2, "st_mtime"), attr(st3, "st_mtime"), delta=delta)
+ self.assertAlmostEqual(
+ attr(st2, "st_mtime"),
+ attr(st3, "st_mtime"),
+ delta=delta
+ )
 
 def test_utime(self):
 def utime(file, times):
test_os passes on FreeBSD, Linux and Mac OS X with that applied. However, the Solaris 10/SPARC box still fails:
AssertionError: 9.5367431640625e-07 not less than 2e-09
But it appears that build is actually picking up utimensat(), which makes the Solaris failures unrelated to the FreeBSD/NetBSD ones. I'll do some more investigating. Might warrant a separate issue.
Larry: thoughts on the test_os.patch as is?