puppeteer: Can not launch Firefox binaries

Steps to reproduce

• Puppeteer version: 8.0.0
• Platform / OS version: Ubuntu 18.04
• Node.js version: 12.22

What steps will reproduce the problem?

1. For this simple script:

import puppeteer from "puppeteer"

(async () => {
    const browser   = await puppeteer.launch({
        product                 : 'firefox',
        headless                : true,
        ignoreHTTPSErrors       : true,
        timeout                 : 60000
    })

    const page      = await browser.newPage()

    await page.goto('http://google.com')

    await browser.close()
})()

The console output is:

(node:19142) UnhandledPromiseRejectionWarning: Error: Could not find expected browser (firefox) locally. Run `PUPPETEER_PRODUCT=firefox npm install` to download a supported Firefox browser binary.
    at FirefoxLauncher.launch (/home/nickolay/workspace/Bryntum/siesta-monorepo/siesta/node_modules/puppeteer/lib/cjs/puppeteer/node/Launcher.js:191:23)
    at async file:///home/nickolay/workspace/Bryntum/siesta-monorepo/siesta/examples/isomorphic_serverless/test.js:3:21
(node:19142) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:19142) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

1. As suggested by the message I do PUPPETEER_PRODUCT=firefox npm install in console.

nickolay@frontier:~/workspace/Bryntum/siesta-monorepo/siesta$ PUPPETEER_PRODUCT=firefox npm install
npm WARN fetch-blob@2.1.1 requires a peer of domexception@^2.0.1 but none is installed. You must install peer dependencies yourself.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.1.3 (node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.3: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})

removed 2 packages and audited 330 packages in 2.726s

32 packages are looking for funding
  run `npm fund` for details

found 2 vulnerabilities (1 low, 1 moderate)
  run `npm audit fix` to fix them, or `npm audit` for details
nickolay@frontier:~/workspace/Bryntum/siesta-monorepo/siesta$ 

The command does not seem to trigger the Firefox binaries dowloading, no progress bar appears. 3. Trying to launch the script results in the same error message

nickolay@frontier:~/workspace/Bryntum/siesta-monorepo/siesta$ node examples/isomorphic_serverless/test.js
(node:19278) UnhandledPromiseRejectionWarning: Error: Could not find expected browser (firefox) locally. Run `PUPPETEER_PRODUCT=firefox npm install` to download a supported Firefox browser binary.
    at FirefoxLauncher.launch (/home/nickolay/workspace/Bryntum/siesta-monorepo/siesta/node_modules/puppeteer/lib/cjs/puppeteer/node/Launcher.js:191:23)
    at async file:///home/nickolay/workspace/Bryntum/siesta-monorepo/siesta/examples/isomorphic_serverless/test.js:3:21
(node:19278) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:19278) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

What is the expected result? I’d expect Puppeteer to lazily download Firefox binaries when its first used. I don’t expect the separate manual installation step.

What happens instead? Can not launch Firefox binaries, despite following the manual installation recommendations.