[Bug] TypeScript 4.2.2 unable to be installed with Yarn 2.4.0

[jacobwgillespie]

Describe the bug

It appears that when attempting to install TypeScript 4.2, which was just released, the latest released version of Yarn (2.4.0) fails to apply patches. Attempting to install or upgrade TypeScript results in the error Cannot apply hunk #6.

It does appear that the unreleased code in master (yarn set version from sources) is able to install TypeScript 4.2.2.

To Reproduce

Note that since this is only an issue for 2.4.0, this reproduction downloads and runs against 2.4.0 rather than master:

Reproduction

const {execFile} = require('child_process');
const {promisify} = require('util');
const execFileP = promisify(execFile);

// Install the latest released version of Yarn
await yarn('set', 'version', 'latest');

// Add helper to call the released version
async function yarnLatest (...args) {
  let stdout;
  try {
    ({stdout} = await execFileP('.yarn/releases/yarn-2.4.0.cjs', args, {
      env: {...process.env, YARN_ENABLE_COLORS: 0, YARN_IGNORE_PATH: 1, YARN_ENABLE_INLINE_BUILDS: 1},
    }));
  } catch (error) {
    error.message += `\n${error.stdout}`;
    throw error;
  }
  return stdout;
}

// Init the local project
await yarnLatest('init');

// Attempt to install TypeScript
const installPromise = yarnLatest('add', 'typescript');
await expect(installPromise).resolves.toBeDefined();

Screenshots

Environment

• OS: macOS
• Node version: 14.15.5
• Yarn version 2.4.0

[arcanis]

Unfortunately as long as microsoft/TypeScript#35206 isn't merged we have to rely on a patch in order to add TypeScript compatibility. Such patches sometimes fail to apply cleanly between versions, and that's what happened here.

On the bright side this particular issue has already been fixed in master, so running yarn set version from sources may be an option for you (although beware, the master branch has a few potentially breaking changes). We'll soon release 3.0.0-rc.1 which will include the fix.

And remember to upvote the TS PR, perhaps a critical mass will convince the TS team to partner on a proper fix 🤞

[jacobwgillespie]

Nice, yea I'm already one of the 90+ upvotes on that PR 👍 🙃

yarn set version from sources does resolve, but I don't necessarily want to upgrade our business projects to a bleeding edge version just yet. We're happy to wait for a released version of Yarn and block on upgrading TypeScript, if it's not practical to resolve on the 2.x Yarn branch.

[JTrippleP]

Beat me to the post!
On the bright side, 4.1.5 is still working so I will be sticking to that until Microsoft adds in official support (hopefully).
I'll get my co-workers to add some upvotes on that.

Thanks

[SimenB]

Is there any way of skipping the patch if I use the node_modules linker? I don't need PnP support, but I would like to update to TS 4.2.

I guess this applies to all the patches you bundle

[Eli-Black-Work]

In some cases, this error can be worked around by adding these lines to package.json:

"resolutions": {
   "typescript": "4.1.5"
}

Specifically, this is useful when you're seeing this error because one of your dependencies depends on TypeScript 4.2.2 but your project doesn't.

Hope that's helpful to someone 🙂

[arcanis]

Is there any way of skipping the patch if I use the node_modules linker? I don't need PnP support, but I would like to update to TS 4.2.

I guess this applies to all the patches you bundle

I'll add this capability to the next release.

[SimenB]

Awesome, thanks @arcanis!

[sportshead]

The link for the error message doesn't work, perhaps a section can be added with a link to this issue?

[araujogui]

Use typescript@~4.1.5 as long as there is no fix to the issue.

[clemyan]

Use typescript@~4.1.5 as long as there is no fix to the issue.

Not directly related to the issue, but as a rule of thumb typescript should be specified with ~ everywhere because its versioning scheme is non-semver.

[arcanis]

@JasonKleban This seems to be a different issue, please open a different thread (with reproduction).

I'll lock this thread for now since the resolution is already in progress (fix is already in master, and with #2543 failing builtin patches won't prevent you from using the packages - the patch will simply be turned off). I'll update once a release is made (ideally we'll make a 2.4.1 that will just include the TS fix, I just have to double-check that the branch didn't diverge too much).

[arcanis]

I've just released Yarn 2.4.1, which formally fixes the compatibility issue with TS 4.2 (no other change in this release). Along with the work mentioned in the previous post I think we can now close this issue, thanks for your patience!