Bug Report

Multiple packages in the monorepo are being built simultaneously when this happens:

// This is where we are building each package to be published.
const results = await pMap(packagePaths, async (packagePath) => buildForNpm({ packagePath, groupName }), {
  // Change to 1 and the problem seems to go away, 
  // but it will take significantly longer to build.
  concurrency: 20 
});

buildForNpm runs tsc --build tsconfig.json --pretty

        if (refBuildInfo.path === buildInfoCacheEntry.path)
                         ^

TypeError: Cannot read properties of undefined (reading 'path')
    at hasSameBuildInfo (/project/node_modules/typescript/lib/tsc.js:105509:26)
    at hasSameBuildInfo (/project/node_modules/typescript/lib/tsc.js:105517:21)
    at getUpToDateStatusWorker (/project/node_modules/typescript/lib/tsc.js:105453:44)
    at getUpToDateStatus (/project/node_modules/typescript/lib/tsc.js:105531:22)
    at getNextInvalidatedProjectCreateInfo (/project/node_modules/typescript/lib/tsc.js:105082:26)
    at getNextInvalidatedProject (/project/node_modules/typescript/lib/tsc.js:105142:20)
    at build (/project/node_modules/typescript/lib/tsc.js:105665:38)
    at Object.build (/project/node_modules/typescript/lib/tsc.js:105863:101)
    at performBuild (/project/node_modules/typescript/lib/tsc.js:106569:73)
    at Object.executeCommandLine (/project/node_modules/typescript/lib/tsc.js:106514:24)

Once the problem happens, the problem will keep happening until the output in cache/outDir is deleted.

The error is thrown here: https://github.com/microsoft/TypeScript/blob/main/src/compiler/tsbuildPublic.ts#L1794

Possibly related to the changes in this PR: https://github.com/microsoft/TypeScript/pull/48784.

This fixes the problem for me. Happy to make a PR if I can figure out how to test it.

-if (refBuildInfo.path === buildInfoCacheEntry.path) return true;
+if (refBuildInfo?.path === buildInfoCacheEntry.path) return true;

🔎 Search Terms

• Parallel builds.
• Concurrent builds.
• race condition.
• randomly failing to build.

🕗 Version & Regression Information

• TypeScript 4.8.2
• This is a crash.
• This changed between versions 4.7 and 4.8.2

⏯ Playground Link

Not able to reproduce with small projects.

💻 Code

This is happening in a large closed-source project.

🙁 Actual behavior

Crashing during build.

🙂 Expected behavior

No crash.