More gracefully fail on `pyproject.toml` error

[eleanorjboyd]

tried going through the "create environment..." flow with a pyproject.toml file but I had an error since my pyproject.toml file was incorrectly formatted. Would be good if the error message was better or it failed more gracefully

 Resolved Python Environment /Users/eleanorboyd/python-envs-scenarios/existing-env-folder/.venv/bin/python
2025-05-14 09:19:39.308 [info] Running: uv pip install --python /Users/eleanorboyd/python-envs-scenarios/existing-env-folder/.venv/bin/python -e /Users/eleanorboyd/python-envs-scenarios/existing-env-folder
2025-05-14 09:19:39.378 [info] error: Failed to extract static metadata from `pyproject.toml`
  Caused by: TOML parse error at line 6, column 8
  |
6 | name = "existing env folder"
  |        ^^^^^^^^^^^^^^^^^^^^^
Not a valid package or extra name: "existing env folder". Names must start and end with a letter or digit and may only contain -, _, ., and alphanumeric characters.

[StellaHuang95]

I looked into the issue and found several problems with the current user experience:

1. Although the popup window shows that an error occurred, users only see a generic “Error managing packages” message with no context. It doesn’t mention pyproject.toml at all. The actual error is buried in the logs, and users have to click “View Output” and scroll through the output to find the real message.

2. The environment is created successfully first, but the package installation then fails, leaving users with a half-working environment in a confusing state.

I’m thinking of improving the user experience by adding early validation. We could validate pyproject.toml when the user clicks Create Environment. If it’s invalid, we would show a warning with the error message and give the user three options: Open pyproject.toml, Create anyway, or Cancel, which corresponds to open the file, proceed despite the issue, or stop the process.

One challenge is that the warning dialog has limited space, so the error message will need to be concise and easy to understand. Benefit of this approach is that once we start parsing pyproject.toml up front, we can also validate other formatting and configuration issues early based on relevant PEPs, making the fix more general.

Eleanor Boyd (@eleanorjboyd) What do you think about this approach?

[eleanorjboyd]

Thanks for this detailed investigation! When you say the "create environment" step which one are you talking about specifically? Like before this one?

my worry is that if a user selects "quick create" we will try to use the pyproject.toml but if the user selects "venv" and configures it themself they could choose to not use the pyproject.toml to create their environment and thus present the issue unnecessarily.

So I love the 3 options and doing early validation is good but I just want to make sure we aren't confusing users who aren't going to end up selecting the pyproject.toml

[eleanorjboyd]

closed by #1066

[amunger]

tried adding some malformed stuff to a pyproject.toml, and it just seems to ignore the file entirely. is that expected?

[amunger]

specifically, removing a ", just creates the venv without any packages installed:

dependencies = ["httpx]