Exit codes

tn-venv uses a small, stable set of process exit codes so automation can react without parsing output.

Code	Meaning	Typical causes
0	success	environment created; --list-pythons, --dry-run, --help, --version completed
1	execution failure (TNError)	destination already contains an environment; interpreter not found; ensurepip/pip failed; lock timed out; requirements file missing
2	usage / configuration error	unknown flag; invalid choice; --symlinks with --copies; malformed config file or env var; unknown activator
130	interrupted	Ctrl+C during creation

Rules of thumb for scripts:

• 2 means fix the invocation — retrying unchanged will fail again.

• 1 means fix the environment — the lock, the network, or the destination state.

• The error class is always printed as part of the message, and -vv shows the failing subprocess command and its full output.

cli_run() (see Python API reference) returns exactly these codes, so embedding code can rely on the same contract.