1411350 - frequent "IOError: [Errno 0] Error" in c:\mozilla-build\python\lib\logging\__init__.py, line 872 using Mintty

Status: RESOLVED FIXED

(Firefox Build System :: MozillaBuild, task)

Description

[Myk Melez [:myk] [@mykmelez]]

After updating my Windows 10 VM to the Fall Creator's Update, I'm seeing frequent errors in c:\mozilla-build\python\lib\logging\__init__.py while building:

>  Traceback (most recent call last):
>   File "c:\mozilla-build\python\lib\logging\__init__.py", line 872, in emit
>     stream.write(ufs % msg)
> IOError: [Errno 0] Error
> Logged from file logging.py, line 54

The errors don't cause the build to fail.  Nor do they prevent build process output to the terminal.  Although they do make the output harder to read, as they occur hundreds (thousands?) of times during a clobber build.

Comment 1

[Myk Melez [:myk] [@mykmelez]]

This appears specific to Mintty, as the problem disappears when I revert to the default terminal app.  Mintty also seems to crash periodically after spewing a bunch of garbage characters to the screen.

Comment 2

[Gregory Szorc [:gps]]

errno being 0 is... special.

So, write() appears to error. But for whatever reason errno() likely is returning 0 when Python queries it to see what the actual failure was. I have no clue what that is about.

This could very well be a bug in mintty, assuming we're writing to stdout or stderr here.

Comment 3

[Mitchell Hentges [:mhentges] 🦀]

In my testing in this bug, modern mintty doesn't have this issue.