Thoughts on handling forked dependencies? Our monorepo workflow sometimes requires us to (hopefully temporarily) fork dependencies. When that happens, our pre-pants workflow was as follows: 1. fork the dep to our own separate git repo, not the monorepo (ex github:alextremblay/dependency-name 2. update pyproject.toml dependency from

dependency-name >= ...

to

dependency-name @ git+<https://github>....

3. add this fork as a git submodule to the monorepo 4.

pip install -e custom-forks/dependency-name

so we can iterate and test our change to the fork live within our activated venv 5. commit / push changes to the forked repo so that our published packages which depend on this forked dep can pull / install the updated code from github when deployed in the wild 6. work on getting our changes merged upstream (can sometimes take months or longer 😞 ) I'm trying to achieve the same with pants, but it's proving to be difficult. setting the dependency to point to a git repo works fine (unless you try to pin lockfile deps with a constraints file, at which point it just entirely blows up But I can't figure out how to tell pants to override that dep with a local editable install when exporting the venv or running any tasks which include that dep Thoughts?

Re the parenthetical re constraints, did I hallucinate this?: https://github.com/pex-tool/pex/issues/3089 Have you upgraded Pex and still hit the constraints issue @stale-twilight-79248?

you did not. U[pgrading pex DID solve that issue, but i then immediately ran into another constraints related issue. at that point i got so frustrated i just gave up on the whole uv lock -> constraints -> pants lock idea. I will probably eventually get back to it, repro the error and open an issue

That would be great. It's slightly cruel to bait me with a bug I can't see. I don't like Pex bugs!

It's not 100% straightforward, but you can build the submodule via its own setup.py using Pants's "local dists" concept, and then consume that on local runs. See here for example: https://github.com/benjyw/example-python/compare/main...forked_thirdparty_dep

that's awesome! Thank you guys! lol sorry @brief-scientist-13682, i can see how that would suck. I'll carve out some time today to repro and open an issue. @happy-kitchen-89482 have you any idea how to get pants to

pip install -e

the local fork when exporting a venv?

So, Pex can lock editable (although its not easy right now, a requirements.txt as input is required):

:; git clone <https://github.com/VaasuDevanS/cowsay-python>
:; cat requirements.txt 
-e cowsay-python/
:; pex3 lock create -r requirements.txt --indent 2 -o lock.json
# Note `"editable": true,` in the artifacts list below:
:; jq .locked_resolves[0].locked_requirements lock.json 
[
  {
    "artifacts": [
      {
        "algorithm": "sha256",
        "editable": true,
        "hash": "111eb24cead5476d6384dfe692e61f73a897275b48373bcc5385c0b4bfbf7dc2",
        "url": "file:///home/jsirois/support/pants/slack/3-4-2026/cowsay-python"
      }
    ],
    "project_name": "cowsay",
    "requires_dists": [
      "coverage; extra == \"test\"",
      "pytest; extra == \"test\""
    ],
    "requires_python": ">=3.8",
    "version": "6.1"
  }
]

But Pex cannot install as editable:

:; pex3 venv create --lock lock.json -d editable-venv

# Edit local clone and show this breaks it:
:; echo "INVALID" >> cowsay-python/cowsay/__main__.py 
:; PYTHONPATH=cowsay-python/ python -mcowsay -t 'Moo!'
  ____
| Moo! |
  ====
    \
     \
       ^__^
       (oo)\_______
       (__)\       )\/\
           ||----w |
           ||     ||
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/jsirois/support/pants/slack/3-4-2026/cowsay-python/cowsay/__main__.py", line 34, in <module>
    INVALID
NameError: name 'INVALID' is not defined

# But the venv has pristinely installed copies and no break:
:; editable-venv/bin/python -mcowsay -t 'Moo!'
  ____
| Moo! |
  ====
    \
     \
       ^__^
       (oo)\_______
       (__)\       )\/\
           ||----w |
           ||     ||

That said @stale-twilight-79248 re: > But I can't figure out how to tell pants to override that dep with a local editable install when exporting the venv or running any tasks which include that dep Why are you trying to do things differently than item 4 in your initial list? Can't you just export a venv using the existing Pants means and then, exactly as in 4. above:

pip install -e custom-forks/dependency-name

? If not, what is the error?

Hi @brief-scientist-13682 thanks for this! Apologies for not getting back to you with a repro. I had to step away from my pants adoption journey for quite a while due to a number of factors, but I'm back at it now. I've reproduced the error that i stumbled into after updating pants to use pex 2.86.1, and i've reopened the original pants issue with a new comment outlining it here: https://github.com/pantsbuild/pants/issues/23040#issuecomment-4200637668 if you wish to drill into it more, the exact git commit in my momorepo which will produce this error is https://github.com/uoft-networking/tools/tree/3f68310b5a2e53c00075c3d016671e51be724724

Thanks - I'll take a look.

thanks john, i'm going through the links now, there's.... a lot