Title: Launcher fails on custom command starting with "python"
Type: behavior Stage:
Components: Windows Versions: Python 3.8, Python 3.7, Python 3.6, Python 3.5, Python 3.4, Python 2.7
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: mrh1997, paul.moore, steve.dower, tim.golden, zach.ware
Priority: normal Keywords:

Created on 2017-10-26 17:01 by mrh1997, last changed 2017-11-08 16:55 by mrh1997.

Messages (4)
msg305072 - (view) Author: Robert (mrh1997) Date: 2017-10-26 17:01
In the "py.ini" file it is possible to specifiy customized commands (see

Unfortunately it is not possible to specify custom commands beginning with  one of the buildin names (i.e. "python" or "/usr/bin/python"). 

This means that if I want to provide a virtual command like "python-xyz" I get an error message "Invalid version specification: '-xyz'" instead of running the executable assigned to python-xyz.

I would provide a Pullrequest if you accept this change in behaviour.
msg305863 - (view) Author: Robert (mrh1997) Date: 2017-11-08 15:56
I am still waiting for a OK (or denial) of my proposed Modification.

I want to avoid that I start coding and when I am finished the PSF denies my PullRequest.

Is anybody out there who can decide this or at least lead a discussion?
msg305872 - (view) Author: Paul Moore (paul.moore) * (Python committer) Date: 2017-11-08 16:02
Personally I don't see the value (in general, I don't see much use for the whole custom command idea - making the launcher into a generalised shebang processor was never really a core feature). But I'm not going to say no if others find it useful. Call me -0 on the proposal.
msg305880 - (view) Author: Robert (mrh1997) Date: 2017-11-08 16:55
Of course I do not know the initial ideas/philosophy of the launcher.

But the current implementation supports these custom commands (for whatever reason). Thus I'd say they should work "properly". My view of "properly" is that the implementation matches the documentation which is currently definitely not the case.

Of course one could add an extra passus to the docs like: "custom command names must not start with 'python'". But why include a special case (and make it less intuitive) without need?

By the way: We have a use case for this custom commands and I could image others had, too. Or how came that they were included?
Date User Action Args
2017-11-08 16:55:53mrh1997setmessages: + msg305880
2017-11-08 16:02:31paul.mooresetmessages: + msg305872
2017-11-08 15:56:19mrh1997setmessages: + msg305863
2017-10-26 17:01:08mrh1997create