May be a dumb question, but in upgrading to pants 2.11 is there any way to get

python_library

(which is deprecated) and

python_sources

to co-exist? I currently have a setup that would allow me to use different version of pants in parallel while I upgrade small pieces at at time (rather than have 200+ BUILD files changed at one time and risk breaking everything in the process). Even if I told pants to ignore unknown types, that would be OK

Hi! I can't think of a good way to do that Instead, what you can do is stay on 2.8 for now and silence the deprecation by setting `ignore_warnings`: https://www.pantsbuild.org/docs/upgrade-tips#ignore-deprecation-messages-with-ignore_warnings. Keep using

python_library

at first Over several PRs, upgrade to

python_sources

while still on Python 2.8 Once you are fully done upgrading, you can upgrade to 2.9, which I think was the first Pants version to drop

python_library

I'll try 2.8 and see what happens, thanks!

What Pants version are you on now?

1.30, but in trying to get an old plugin migrated to use engine v2, it was easiest to go to 2.X as it wasn't 2 year out of date

Cool. I'm pretty conflicted on the best way in 2022 to migrate from 1.30 to 2.x 🤷originally, we recommend going to 2.0, and then upgrade to 2.1, then 2.2 and so on And that you don't actually have to land the upgrade to 2.0 etc. But at least locally, get

./pants list ::

and stuff working, then go to the next minor version -- The plugin complicates things tho

Yeah, what I've found is that following the docs for 1.30, I can't seem to get the magic sauce right so that the plugin is recognized by engine v2, so I just bit the bullet and tried 2.11 since that is at least supported. However there are so many changes with respect to the build files that I'm having to update just about everything at once. Plus, to make matters even more entertaining, we're running python 3.6.14, but I've found that pants 2.X doesn't want to work with anything less than 3.7. If I could de-risk and get things working in 1.30 for now, then I can upgrade to python 3.7, then upgrade pants again I could verify that our code works under 3.7 first in a controlled manner

Plus, to make matters even more entertaining, we're running python 3.6.14, but I've found that pants 2.X doesn't want to work with anything less than 3.7.

Hm, Pants should have zero opinion on what Python version your own code uses. It only needs a 3.7 interpreter to run the tool itself There are folks running Python 2 with Pants 2.11

Oh, I must've done something wrong initially then, that's awesome! I guess that means I can upgrade to 2.11 without some of the risk. Just tested and was able to execute things with 3.6.14 using pants 2.11

when making long leaps like this, it is fairly common to define `v2` macros which map from one version’s syntax to the other… we don’t really have a good library of these macros though, because it’s dependent on both versions

May be a dumb question

Also definitely no dumb questions in this Slack 🙂 upgrading from 1.30 can be a challenge, but we think the v2 experience is dramatically better. We're very happy to help w/ questions like this!

The macros part has been really helpful so far, I was able to extend things a bit so it seems happy for the most part. Only bit that I'm still hung up on is adding the

sources

field to

pex_binary

. I'm not sure what the proper way to add that functionality back similar to what

sources

was at least in pants 1.30.

create a

python_sources

target, and have the

pex_binary

target explicitly depend on it, probably…?