[CLI]: install-browser --no-shell is rejected with "Unknown option: --shell" #42804

playwright-cli install-browser advertises --no-shell in its own --help, but passing it
fails with Unknown option: --shell and exit code 1. Reproduced on the latest release, 0.1.21.
Because every spelling is rejected, there is currently no supported way to install Chromium
through playwright-cli without also downloading chromium-headless-shell — which is exactly
what the flag is for. That is an extra ~261 MB on disk for a setup that only ever runs headed.

The sibling flag --only-shell, on the same command, is accepted — so the failure is specific to
the negated form, not to install-browser.

Reproduction (uses --dry-run, so nothing is downloaded):

npx @playwright/[email protected] install-browser chromium --dry-run     # lists Chrome Headless Shell
npx @playwright/[email protected] install-browser chromium --no-shell --dry-run

Expected: --no-shell is accepted and Chromium is installed without
chromium-headless-shell, matching the help text and npx playwright install chromium --no-shell.

Actual:

$ npx @playwright/[email protected] install-browser chromium --no-shell --dry-run
Unknown option: --shell
(exit 1)

The option is listed by the command itself:

$ npx @playwright/[email protected] install-browser --help
Options:
  --only-shell                only install headless shell when installing chromium
  --no-shell                  do not install chromium headless shell

A plain --dry-run confirms the shell is part of a Chromium install:

$ npx @playwright/[email protected] install-browser chromium --dry-run
Chrome for Testing 154.0.8037.0 (playwright chromium v1246)
FFmpeg (playwright ffmpeg v1011)
Chrome Headless Shell 154.0.8037.0 (playwright chromium-headless-shell v1246)

Every spelling tried on 0.1.21, each exiting 1:

$ npx @playwright/[email protected] install-browser chromium --no-shell=true --dry-run
<prefix>/playwright-core/lib/tools/cli-client/minimist.js:56
        throw new Error(`boolean option '--${key}' should not be passed with '=value', use '--${key}' or '--no-${key}' instead`);
              ^

Error: boolean option '--no-shell' should not be passed with '=value', use '--no-shell' or '--no-no-shell' instead
    at minimist (<prefix>/playwright-core/lib/tools/cli-client/minimist.js:56:15)
    at program (<prefix>/playwright-core/lib/tools/cli-client/program.js:64:45)
    at main (<prefix>/@playwright/cli/playwright-cli.js:36:3)

That message recommends --no-shell, the spelling that fails, and surfaces as an unhandled stack
trace rather than a CLI error.

Likely cause. Both pieces are present on current main, which matches the behaviour being
identical on 0.1.19 and 0.1.21:

• packages/playwright-core/src/tools/cli-daemon/commands.ts declares the option under the
  literal key ['no-shell'].
• packages/playwright-core/src/tools/cli-client/minimist.ts rewrites any --no-<x> argument to
  key <x> with value false, so --no-shell arrives as the key shell.
• Validation finds no declared shell option and reports it — the observed Unknown option: --shell. --only-shell is unaffected because its name carries no no- prefix.

Environment: @playwright/cli 0.1.21 (bundling playwright-core
1.64.0-alpha-1789764292000), run via npx. Also reproduced identically on 0.1.19 installed
globally. Linux (Arch-based), kernel 7.2.6, x86_64, Node v26.8.2.

Related, not duplicates:

• [Bug]: error: unknown option '--no-shell' #34487 — same error phrase on npx playwright install, but that was v1.47.1 before the flag
  existed (fixed by upgrading). Here the flag exists on the latest release, --only-shell works,
  and the rejected name comes back mangled as --shell.
• why playwright-cli install-browser no useful, but use npx playwright install chrome #41631 — shows the same install-browser --dry-run listing that includes Chrome Headless Shell
  alongside Chromium; it does not touch --no-shell.

Workaround — skip the call when the browser is already installed, so the shell is not pulled
in on repeat runs:

compgen -G "$PLAYWRIGHT_BROWSERS_PATH/chromium-*" >/dev/null ||
  playwright-cli install-browser chromium