The following is a simplified version of the toml file example from the mypy documentation:

[tool.mypy]
python_version = "3.7"
warn_return_any = true
warn_unused_configs = true[[tool.mypy.overrides]]
module = ["somelibrary"]
ignore_missing_imports = true

I am using this configuration in a project where I have a third party library (here named "somelibrary") that is missing type hints and thus causes a lot of spam in the mypy report.

The global mypy configuration is picked up, so I know the overall setup is fine, but whenever I switch ignore_missing_imports in the somelibrary override to true, mypy still behaves as if I had left it to false (I used this same option in the global mypy configuration to make sure to things worked the expected way, which is the case).

I'm using the (currently) latest mypy version, 0.931.

Am I doing something wrong? Is mypy bugged? Something else?

You should add your project to overrides. Lets assume your project is called "my_project" and your library/module "somelibrary" is directly under your "my_project" folder. The toml file should look like this:

[tool.mypy]
python_version = "3.7"
warn_return_any = true
warn_unused_configs = true[[tool.mypy.overrides]]
module = "my_project.somelibrary"
ignore_missing_imports = true