I ran the Python test suite on Windows on a freshly installed Python 3.7a1 and I got errors: bpo-31606.

I created a separated issue for tests failing because my disk has low free space.


On my Windows VM, I have a single 40 GB disk with 1.36 GB free.

C:\Users\haypo\AppData\Local\Programs\Python\Python37>python -m test -v -u all test_largefile

======================================================================
ERROR: test_truncate (test.test_largefile.PyLargeFileTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\test\test_largefile.py", line 37, in setUp
    f.flush()
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\_pyio.py", line 1226, in flush
    self._flush_unlocked()
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\_pyio.py", line 1233, in _flush_unlocked
    n = self.raw.write(self._write_buf)
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\_pyio.py", line 1630, in write
    return os.write(self._fd, b)
OSError: [Errno 28] No space left on device

(other tests fail with similar message)



test_io:

======================================================================
ERROR: test_large_file_ops (test.test_io.CIOTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\test\test_io.p
y", line 574, in test_large_file_ops
    self.large_file_ops(f)
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\test\test_io.p
y", line 355, in large_file_ops
    self.assertEqual(f.write(b"xxx"), 3)
OSError: [Errno 28] No space left on device

======================================================================
ERROR: test_large_file_ops (test.test_io.PyIOTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\test\test_io.py", line 574, in test_large_file_ops
    self.large_file_ops(f)
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\test\test_io.py", line 355, in large_file_ops
    self.assertEqual(f.write(b"xxx"), 3)
  File "C:\Users\haypo\AppData\Local\Programs\Python\Python37\lib\_pyio.py", line 1630, in write
    return os.write(self._fd, b)
OSError: [Errno 28] No space left on device

This is expected behavior, isn't?

> This is expected behavior, isn't?

I would prefer that the test skips itself when the disk is full: on "OSError: [Errno 28] No space left on device".

Or maybe largefile resource should be excluded from "all"... at least on Windows, since NTFS doesn't see to support files full of zeros without accounting zero bytes (seek + write 1 byte: NTFS counts the seek in the disk space).

Definitely the test shouldn't be quietly skipped! If you enable the "largefile" resource, but the test can't write large file, this is either a bug in the tested code, or an error in the test, or misconfiguration.

We already have the "extralargefile" resource which is excluded from "all". "largefile" is for moderately large files, around 2 GiB.

> "largefile" is for moderately large files, around 2 GiB.

largefile creates files larger than 2 GB. Extract of test_largefile:

# size of file to create (>2GB; 2GB == 2147483648 bytes)
size = 2500000000

My VM has less than 2 GB free: only 1.36 GB free.

largefile - It is okay to run some test that may create huge
                files.  These tests can take a long time and may
                consume >2GB of disk space temporarily.

I understand this as 2GB is a minimum free disk space for tests without "largefile". Tests with "largefile" need more free disk space.


Accordingly the bigmemtest decorator is used for tests that consume >1GB of RAM.

According to Serhiy's comment, largefile shouldn't be used with less than 2 GB of free disk space. It was my fault, it's not a bug ;-)