Adopting TOML 1.1?

[effigies (Chris Markiewicz)]

@mgorny

Given that the common workflow for a pure Python package is to:

• build the wheel once, usually using the most recent Python version (or uv)
• test the package against all Python versions, usually working on sources directly

…we’re bound to see CI workflows succeeding with TOML 1.1-capable tool and then primarily downstreams (and sometimes users) reporting issues when they happen to use other tools.

I found this claim surprising. I have not encountered this as a common pattern. The most common thing I see is a job matrix that installs the package with [test] extras and calling pytest. That installation should trigger an issue on TOML 1.1 with Python <=3.14.

I may be wrong, but I feel like the dangers of testing without installing have bitten enough projects over the years that I just never see it anymore.