Installation and project Python

project Python ... does not match

Run m3 setup from the project root. It installs the SDK version matching the standalone CLI into the selected isolated environment. If M3 selected the wrong environment, pass --python PATH to setup and doctor.

Missing pytest, SQLite, or judge support

Run m3 setup. A direct SDK installation needs the applicable extras, such as sf-m3[pytest,storage,judge].

Refusing to install into a global Python

Create or activate an isolated environment, then rerun setup. M3 refuses to modify a system/global Python.