local_env¶

The environment of a local run with snapshots: a venv of the run.

A run of the local backend with snapshots (--snapshot) must not install them into the environment of the service, the one of the user. The backend creates a venv per run in .simrun/envs/<run>/venv, which sees the packages of the service through a path file (BASE_PTH), installs the snapshots into it as editable packages from shadow trees in .simrun/envs/<run>/sources/ (simrun.worker.shadow_tree), and starts the harness with its python; a command task finds it first on PATH. The venv is removed at the end of the run.

The snapshots are installed without their dependencies, which the environment of the service has, with uv (on PATH or the uv package), else with pip; their build backends come from the index or the cache of the installer, as for any build.

BASE_PTH `module-attribute` ¶

BASE_PTH = '~simrun-base.pth'

The path file of the packages of the service in the venv of a run; named to sort after the path files of the snapshots (site reads them in the order of their names), so a snapshot comes before the same package of the service.

RunEnvironmentError ¶

Bases: RuntimeError

The venv of a run cannot be created or the snapshots cannot be installed.

base_site_dirs ¶

base_site_dirs()

The site directories of this interpreter, the user site when enabled.

installer ¶

installer(python)

The command which installs into the venv of python, before its arguments.

Raises:

Type	Description
`RunEnvironmentError`	Neither uv nor pip is installed.

create ¶

create(directory, snapshots, log, cancelled=lambda: False)

Create the venv of a run and install its snapshots into it.

Parameters:

Name	Type	Description	Default
`directory`	`Path`	The directory of the environment of the run, replaced.	required
`snapshots`	`list[str]`	The paths of the snapshots.	required
`log`	`BinaryIO`	Where the output of the installer goes.	required
`cancelled`	`Callable[[], bool]`	Polled while the installer runs; when it holds, the installer is killed.	`lambda: False`

Returns:

Type	Description
`Path`	The python of the venv.