To reproduce:

Expected

1. clone this repo
2. ensure your npm version is <= 8.5.3: npm i -g npm@8.5.3
3. in root of project run: npm i --foreground-scripts

Expect to see message with ⭐️⭐️⭐️⭐️:

➜  npm-8.5.4-no-lifecycle-scripts git:(main) ✗ npm i --foreground-scripts
(#########⠂⠂⠂⠂⠂⠂⠂⠂⠂) ⠋ idealTree: timing idealTree Completed in 9ms
> proj-w-postinstall-dep@1.0.0 postinstall
> echo "⭐️⭐️⭐️⭐️ In >=8.5.4 this is never echoed. ⭐️⭐️⭐️⭐️"

⭐️⭐️⭐️⭐️ In >=8.5.4 this is never echoed. ⭐️⭐️⭐️⭐️

up to date, audited 3 packages in 294ms

found 0 vulnerabilities

Bug

1. ensure your npm version is >= 8.5.4: npm i -g npm@8.5.4
2. rm -rf node_modules to start repository fresh (not needed, just a sanity check)
3. in root of project run: npm i --foreground-scripts
4. 💥 postinstall echo message is not printed:

Message with ⭐️⭐️⭐️⭐️ is missing from output:

➜  npm-8.5.4-no-lifecycle-scripts git:(main) ✗ npm i --foreground-scripts

added 1 package, and audited 3 packages in 326ms

found 0 vulnerabilities