Pip conflict resolution update: 2020-resolver

[lucbouge]

Dear colleagues,

Thank you so much for your excellent software. I use it on a daily basis to update my Python configuration.

I have just been warned by pip people that their dependency conflict resolution procedure is about to change. This is welcome, as it is pretty simplistic as of now, whereas other package management software feature advanced strategies.

Error: ERROR: After October 2020 you may experience errors when installing or updating packages. 
This is because pip will change the way that it resolves dependency conflicts.

Reference: https://blog.python.org/2020/07/upgrade-pip-20-2-changes-20-3.html

It took me some time to understand how to tell pip_upgrade_outdated about it, as I missed the line Any unknown arguments will be passed to pip in the help message.

pip_upgrade_outdated --pip_cmd 'pip3' --exclude pip --use-feature=2020-resolver

I would suggest to make --use-feature=2020-resolver as a default option from now on and to issue a warning to the user.

By the way, I would also suggest to exclude pip by default from the update. Pip updating pip is likely to run into trouble when a new version of pip is issued. A warning would be a better option.

Best regards,

Luc.

[defjaf]

Hi Luc,

Thanks -- I'm glad you find the software useful.

I note that the "error" message doesn't actually seem to affect the actual behaviour and as far as I can tell in most cases the --use-feature flag doesn't have much of an effect. It will go away in two months, in any case!

I have never had any problems upgrading pip with my code, but you are free to add -x pip! I do have a long-term plan to add a config file which would allow you to specify default options, but I haven't had time to implement that...

Yours,

Andrew

[lucbouge]

Yes, I agree that this is only a warning, not an error. Regarding pip, I experienced problems upgrading it, as I am using the HomeBrew package manager on a Mac. Pip is installed in the Python package. For some strange reason, the management of pip in this package is not compatible with the management of pip by pip itself. The locations are not the same, and some files are just physical links in the one, and real copies in the other. I complain at the HomeBrew helpdesk, but with no effect, at least until now. The only way to do has been to prevent pip updating pip. Thanks again for the software! Luc.

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Le 12 août 2020 à 11:59, Andrew Jaffe ***@***.***> a écrit : u find the software useful. I note that the "error" message doesn't actually seem to affect the actual behaviour and as far as I can tell in most cases the --use-feature flag doesn't have much of an effect. It will go away in two months, in any case! I have never had any problems upgrading pip with my code, but you are free to add -x pip! I do have a long-term plan to add a config file which would allow you to specify default options, but I haven't had time to implement that... Yours,

[defjaf]

Hi Luc,

Ah, I use the python.org version of Python, which can just upgrade pip itself. But since it's not a general problem, I do recommend just using -x pip. As I said, I will try to implement a config file at some point which would allow making this permanent without showing on the command line.