#22787 `pex` fails when a v2.29 dependency override is used Issue created by lowvoltage Describe the bug When a transitive dependency override is configured,

pants run

,

pants package

, etc. fail to run. Pants version 2.29.0 OS MacOS and Linux, or both Additional info Minimal setup to reproduce. We add

black

as a top-level dependency and override the version of its transitive dependency, `click`:

pants.toml

[GLOBAL]
pants_version = "2.29.0"
backend_packages = ["pants.backend.python"]

[python]
interpreter_constraints = ["==3.12.*"]
enable_resolves = true
default_resolve = "python-default"

[python.resolves]
python-default = "python-default.lockfile"

[python.resolves_to_overrides]
python-default = [
    "click==7.1",  # A transitive dependency of `black`: click>=8.0.0
]

main.py

import black  # Do not remove this import

if __name__ == '__main__':
    print('Hello, World!')

BUILD

python_sources()

python_requirement(
    name="requirements",
    requirements=["black"],
)

--- Generating the lockfile works fine, the correct overridden

click==7.1

is picked up:

❯ pants generate-lockfiles --resolve=python-default
17:54:30.67 [INFO] Initializing scheduler...
17:54:30.96 [INFO] Scheduler initialized.
17:54:34.10 [INFO] Completed: Scheduling: Find interpreter for constraints: CPython==3.12.*
17:54:39.34 [INFO] Completed: Generate lockfile for python-default
17:54:39.34 [INFO] Completed: Scheduling: Generate lockfile for python-default
17:54:39.36 [INFO] Wrote lockfile for the resolve `python-default` to python-default.lockfile

Lockfile diff: python-default.lockfile [python-default]

==                      Added dependencies                      ==

  black                          25.9.0
  click                          7.1
  mypy-extensions                1.1.0
  packaging                      25.0
  pathspec                       0.12.1
  platformdirs                   4.5.0
  pytokens                       0.2.0

However, trying to run the code fails:

❯ pants run main.py
17:55:50.74 [INFO] Completed: Scheduling: Building local_dists.pex
17:55:50.78 [INFO] Completed: Scheduling: Test binary /bin/bash.
17:55:52.75 [INFO] Completed: Building 1 requirement for .pex from the python-default.lockfile resolve: black
17:55:52.75 [INFO] Completed: Scheduling: Building 1 requirement for .pex from the python-default.lockfile resolve: black
17:55:52.75 [ERROR] 1 Exception encountered:

Engine traceback:
  in `run` goal

ProcessExecutionFailure: Process 'Building 1 requirement for .pex from the python-default.lockfile resolve: black' failed with exit code 1.
stdout:

stderr:
The --override option cannot be used when resolving against a lock file. Only overrides already present in the lock file will be applied.

Examining the command being run shows a

pex

call with

... --lock python-default.lockfile ... $'--override=click==7.1' ...

pantsbuild/pants