Check Plain Env

Always use the skill load-plain-reference to retrieve the ***plain syntax rules — but only if you haven't done so yet.

This skill answers one question: **does the host machine have everything the *plain project needs to render and test? It reads the project, derives the requirement list, probes the machine, and returns a report. It never installs anything itself — that decision belongs to the user.

When to run

• **First time you open a *plain project on a new machine — before the first codeplain <module>.plain or ./test_scripts/run_unittests*.sh invocation. This is the most common case.
• At the start of forge-plain Phase 3 environment verification — forge-plain historically did this inline; delegate to this skill instead so the same check runs the same way everywhere.
• After add-feature — when the new feature brought in a new dependency (a new framework, a new service, a new package manager) the project didn't need before.
• Before a real render — alongside plain-healthcheck. plain-healthcheck answers "are the specs renderable?"; this skill answers "can this machine render them?". Both should pass.
• Onboarding — when a teammate (or CI runner, or fresh dev container) is about to start using the project.
• Debugging a confusing failure — when a test script exits with "command not found", "module not found", "could not connect", or similar before any test runs.
• On demand — whenever the user asks "what do I need to install for this project?".

This skill is read-only and observational. It does not edit .plain files, scripts, or configs, and it never invokes install commands on the user's behalf.

What this skill does NOT do