pyright cannot parse mixed list TOML 1.0 configuration

[Stealthii]

Describe the bug Utilizing any list in TOML that contains a mix of strings, and dictionaries (such as Tox's modern TOML format specification, or dependency-groups includes) will result in pyright being unable to read the configuration file.

Code or Screenshots Consider the following, TOML 1.0.0 compliant, dependency-groups section of a pyproject.toml:

[dependency-groups]
dev = [
  { include-group = "fix" },
  { include-group = "test" },
  { include-group = "type" },
]
fix = [
  "pre-commit-uv>=4.1.3",
]
pkg-meta = [
  "check-wheel-contents>=0.6",
  "twine>=5.1.1",
  "uv>=0.4.17",
]
test = [
  "anyio>=4",
  "covdefaults>=2.3",
  "devpi-process>=1.0.2",
  "diff-cover>=9.2",
  "pytest>=8.3.3",
  "pytest-cov>=5",
  "pytest-mock>=3.14",
  "trio>=0.25",
  "typing-extensions>=4.0.1",
]
type = [
  "mypy",
  "pyright",
  { include-group = "test" },
]

VS Code extension or command-line

❯ pyright --version
pyright 1.1.385
❯ pyright src
Pyproject file parse attempt 1 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Pyproject file parse attempt 2 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Pyproject file parse attempt 3 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Pyproject file parse attempt 4 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Pyproject file parse attempt 5 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Pyproject file parse attempt 6 error: {"name":"TomlError","fromTOML":true,"wrapped":null,"line":135,"col":28,"pos":4100}
Config file "/Users/pyright/python-example-apiclient-httpx/pyproject.toml" could not be parsed. Verify that format is correct.
0 errors, 0 warnings, 0 informations

Lines 133-137, for reference:

type = [
  "mypy",
  "pyright",
  { include-group = "test" },
]

[erictraut]

Pyright is currently using a toml parser that targets toml 0.5.0. It looks like the toml standard has evolved since 0.5.0, so we may need to adopt a new parser library. This carries risk with it, as there are likely to be new bugs in other libraries.

This library claims to support toml 1.0.0, and it has a fair amount of usage — although not as much as the library that pyright is currently using.

I'll need to do some additional investigation and consider the pros and cons of switching to a new toml parser library.

In the meantime, you can use pyright's native configuration file format "pyrightconfig.json" if you want to use newer syntax in your pyproject.toml file.

[Stealthii]

Thanks @erictraut. I can confirm that pyright with the presence of a "pyrightconfig.json" file, no longer makes attempts to parse "pyproject.toml" and will function correctly.