Deno.run.clearEnv requires invalid --unstable-process flag

[Sembiance]

Version: Deno 1.40.5

Running this code:

const p = Deno.run({cmd : ["pwd"], clearEnv : true});

With: deno run --allow-run test.js
yields: Unstable API 'Deno.run.clearEnv'. The --unstable-process flag must be provided.

That flag doesn't exist.

Trying this: deno run --allow-run --unstable-process test.js
yields: error: unexpected argument '--unstable-process' found