Windows Mercurial Python 3 Installer.

[Tom Hindle]

On 12/2/19 8:33 PM, Matt Harbison wrote:
> One word of caution, you need to run `hg.exe`, not `hg`.  I'm not sure 
> what's going on (I suspect it's at least in part because the legacy 
> stdio environment variable isn't set), but you won't get any output 
> from the latter. 

Thanks for the warning! I am seeing stdout not giving output when 
running hg.exe as well. (using python 3.8) (perhaps I did something 
wrong in the build and PYTHONLEGACYWINDOWSSTDIO isn't set in my hg.exe?)

I see in ui._runpager: (mercurial/ui.py)

that:

os.dup2(pager.stdin.fileno(), procutil.stdout.fileno())

and this SO question and python doc explains to me why this causes a 
problem:

https://stackoverflow.com/questions/52373180/python-on-windows-handle-invalid-when-redirecting-stdout-writing-to-file

https://docs.python.org/3/library/sys.html


But setting the following fixes running both 'hg.exe' + 'python.exe hg'

set PYTHONLEGACYWINDOWSSTDIO=1

Thanks