How to run yarn install on CI without --immutable

[segrey]

We run yarn install on CI, and it fails with https://yarnpkg.com/advanced/error-codes#yn0028---frozen_lockfile_exception.
We'd rather avoid committing yarn.lock, because tests are running against latest yarn berry version and this might imply updating yarn.lock. Actually, we don't need exact installed package versions, so no real need in yarn.lock.

The tests are running on TeamCity CI. As I can see, --immutable is implied if CI or TEAMCITY_VERSION environment variables are set. Unfortunately, it's not enough. Could you please point me out to code that calculates --immutable default value?

[merceyz]

There are a multiple options here so I'll list them

• You can pass the --no-immutable flag to turn it off for the install command

yarn install --no-immutable

• Following the documentation for the configuration (https://yarnpkg.com/configuration/yarnrc) you can use environment variables to turn it off regardless of the command

YARN_ENABLE_IMMUTABLE_INSTALLS=false yarn

• Or you can disable it in the .yarnrc.yml config

yarn config set enableImmutableInstalls false

Could you please point me out to code that calculates --immutable default value?

It's based on ci-info detecting a CI here

berry/packages/plugin-essentials/sources/index.ts

Line 91 in dd043a8

default: isCI,

[wajeehmisbahkhan]

I tried adding YARN_ENABLE_IMMUTABLE_INSTALLS=false to my .env file when deploying firebase functions but it doesn't seem to override the --immutable option (which I assume is being passed as I keep receiving the same lockfile modification forbidden error). Has anyone had luck implementing this solution when deploying firebase functions?

[segrey]

Wow, that was fast! Thank you @merceyz!

[say8425]

yarn install --no-immutable

I'm just curious, there's no --no-immutable option in the yarn install docs. --no-immutable is still works in yarn berry?

[cmoulliard]

Yes - it still works with berry. I'm using it with yarn >= 4.x and github action flow