#20952 Regression: env vars no longer being parsed correctly in `pants.toml` as of Pants `2.22.0.dev2` Issue created by krishnan-chandra Describe the bug A clear and concise description of the bug. I have a section in my

pants.ci.toml

that looks like this:

[python-repos]
indexes.add = [
  "<https://aws:%(env.CODEARTIFACT_AUTH_TOKEN)s@mydomain-myaccountid.d.codeartifact.us-east-2.amazonaws.com/pypi/pypi-internal/simple/>"
]

This is used to connect to AWS CodeArtifact and download some private dependencies from there. It works fine in Pants 2.22.0.dev1, but breaks in 2.22.0.dev2 with the following error + stack trace:

Traceback (most recent call last):
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/bin/pants", line 19, in <module>
    sys.exit(entry_point())
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/bin/pants_loader.py", line 112, in main
    PantsLoader.main()
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/bin/pants_loader.py", line 108, in main
    cls.run_default_entrypoint()
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/bin/pants_loader.py", line 91, in run_default_entrypoint
    exit_code = runner.run(start_time)
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/bin/pants_runner.py", line 76, in run
    bootstrap_options = options_bootstrapper.bootstrap_options
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/util/memo.py", line 1[23](<https://github.com/researchrabbit/six-degrees-backend/actions/runs/9215571975/job/25354208128#step:13:24>), in memoize
    result = func(*args, **kwargs)
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/option/options_bootstrapper.py", line 236, in bootstrap_options
    return self.parse_bootstrap_options(self.env, self.bootstrap_args, self.config)
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa[24](<https://github.com/researchrabbit/six-degrees-backend/actions/runs/9215571975/job/25354208128#step:13:25>)19f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/option/options_bootstrapper.py", line 95, in parse_bootstrap_options
    bootstrap_options = Options.create(
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/option/options.py", line 166, in create
    native_parser = NativeOptionParser(args, env, config.sources(), allow_pantsrc=True)
  File "/home/runner/.cache/nce/ab1acf935c4cc43338c604ae7d0f6aa2419f2415d94eb9cae381601dbba70a61/bindings/venvs/2.22.0.dev2/lib/python3.9/site-packages/pants/option/native_options.py", line 47, in __init__
    self._native_parser = native_engine.PyOptionParser(
ValueError: Unknown value for placeholder `env.CODEARTIFACT_AUTH_TOKEN` in config file pants.ci.toml, section python-repos, key indexes

Pants version Which version of Pants are you using?

2.22.0.dev2

- this regression was introduced between

2.22.0.dev1

and

2.22.0.dev2

OS Are you encountering the bug on MacOS, Linux, or both? Linux Additional info Add any other information about the problem here, such as attachments or links to gists, if relevant. If I had to guess, the regression was probably introduced in this PR. pantsbuild/pants