Ensure `@tailwindcss/cli` recovers from a deleted transitive dependency by RobinMalfait · Pull Request #20137 · tailwindlabs/tailwindcss

RobinMalfait · 2026-06-01T16:42:16Z

This PR fixes an issue where the @tailwindcss/cli can get into a non-recoverable state when any of the transitive dependencies break.

Tailwind CSS has 2 kinds of dependencies:

All your templates
All dependencies that contribute to your configuration such as the input.css, any plugins, any tailwind.config.js files and so on.

When a template changes, we just have to scan for new Tailwind CSS classes and emit a new CSS file. But when the input.css file, or any of its dependencies changes, then we want to perform a full rebuild.

The idea is that your @theme might have changed, or new plugins have been added, or old plugins have been removed.

If you have an input.css file:

@import "tailwindcss";
@config "./tailwind.config.js";

That relies on a custom config: tailwind.config.js:

const theme = require('./my-custom-theme.js');
module.exports = {
  theme
}

If that file relies on yet another file: ./my-custom-theme.js, then changes there should also trigger a full rebuild.

Since we're dealing with JavaScript here, we want to clear the require cache and rebuild the dependency tree such that another change to any of these files triggers a full fresh build.

However, if any of those (transitive) dependencies are deleted, then we will end up in an invalid state. Creating a new compiler will result in a build error. The compiler won't be able to figure out the entire dependency tree, and we're stuck.

Once the user fixes the potentially missing dependency, the watchers will not be watching any of those files because we created a fresh compiler.

With this PR, we fix that by keeping track of old paths and using those while we are still in an invalid state. The moment everything is fixed, a fresh dependency tree is created and everything starts working again without you having to restart the @tailwindcss/cli command.

Fixes: #20113
Closes: #20114
Closes: #20133

Test plan

Added an integration test that removes the transitive dependency. Re-adding that file later will recover the CLI state.

coderabbitai · 2026-06-01T16:47:04Z

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CHANGELOG.md
packages/@tailwindcss-cli/src/commands/build/index.ts

✅ Files skipped from review due to trivial changes (1)

CHANGELOG.md

🚧 Files skipped from review as they are similar to previous changes (1)

packages/@tailwindcss-cli/src/commands/build/index.ts

Walkthrough

This PR improves CLI watch mode reliability when dependencies change or are deleted. It adds a delete method to the test harness filesystem context, implements structured error formatting with colored output helpers, backs up and restores the compiler's dependency-tracking state (fullRebuildPaths) before and after full rebuilds to recover from errors, treats deleted files as rebuild-triggering events rather than ignoring them, and exercises these changes through test fixture corrections and a new test case for dependency removal scenarios.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main fix: ensuring CLI recovery when a transitive dependency is deleted, which is the core objective of all changes.
Description check	✅ Passed	The description comprehensively explains the problem, the solution, and the test plan, directly addressing the issue of CLI entering non-recoverable state when dependencies are deleted.
Linked Issues check	✅ Passed	The PR successfully addresses all linked issues: (`#20113`) rebuilds on deleted dependencies, (`#20114`) forwards delete events and recovers gracefully, and (`#20133`) keeps tracking old paths during invalid state.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing the deleted dependency recovery issue: test fixtures, test harness utilities, error handling, dependency tracking, and changelog are all aligned with the PR objectives.

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coderabbitai

Actionable comments posted: 1

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Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/`@tailwindcss-cli/src/commands/build/index.ts:
- Around line 317-323: The current rollback always restores fullRebuildPaths
from backupRebuildPaths on any watch-time exception; change this so the rollback
only occurs if the dependency tree is actually invalid (i.e., if
createCompiler() did not complete successfully). Introduce a local flag (e.g.,
createdCompiler = false) before the try, set createdCompiler = true immediately
after createCompiler() returns, and in the catch or finally restore
fullRebuildPaths from backupRebuildPaths only when createdCompiler is false;
reference the existing variables backupRebuildPaths and fullRebuildPaths and the
createCompiler() call to locate where to add the flag and conditional rollback.

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Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

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📒 Files selected for processing (3)

integrations/cli/index.test.ts
integrations/utils.ts
packages/@tailwindcss-cli/src/commands/build/index.ts

greptile-apps · 2026-06-01T16:51:01Z

Confidence Score: 4/5

The recovery logic is correct and the approach is sound, but there is a known runtime issue in the catch block that would prevent the 'Done in' timing line from printing and would cause the new integration test to hang — this was already flagged in a prior review thread and has not yet been addressed.

The backupRebuildPaths snapshot-and-restore mechanism is logically correct across all traced scenarios (first failure, consecutive failures, recovery). The watcher change to enqueue deleted paths is also correct. However, the start timing variable is declared with let inside the try block (line 275), making it out-of-scope in the catch block added by this PR (line 436). Under ES2022 block scoping — which this package targets — evaluating start in the catch body will throw a ReferenceError at runtime, meaning the 'Done in' line never prints and the new test's await process.onStderr((m) => m.includes('Done in')) after the error will hang indefinitely.

packages/@tailwindcss-cli/src/commands/build/index.ts — specifically the catch block around line 436 where start (declared inside the try block) is used.

_{Reviews (2): Last reviewed commit: "update changelog" | Re-trigger Greptile}

RobinMalfait added 3 commits June 1, 2026 15:32

fix incorrect folder name

44ca093

add ability to delete files during integration tests

2f59011

add failing test

e797904

RobinMalfait requested a review from a team as a code owner June 1, 2026 16:42

coderabbitai Bot reviewed Jun 1, 2026

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Comment thread packages/@tailwindcss-cli/src/commands/build/index.ts

greptile-apps Bot reviewed Jun 1, 2026

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Comment thread packages/@tailwindcss-cli/src/commands/build/index.ts

Comment thread packages/@tailwindcss-cli/src/commands/build/index.ts Outdated

RobinMalfait added 3 commits June 1, 2026 18:57

print errors during builds

aaea970

ensure @tailwindcss/cli builds recover from deleted files

8e09524

update changelog

a8c2357

RobinMalfait force-pushed the fix/issue-20113 branch from ed0ebb6 to a8c2357 Compare June 1, 2026 17:02

RobinMalfait merged commit 44818a6 into main Jun 1, 2026
9 checks passed

RobinMalfait deleted the fix/issue-20113 branch June 1, 2026 17:15

This was referenced Jun 1, 2026

CLI watch does not rebuild when a tracked dependency is deleted #20113

Closed

fix: trigger full rebuild when a tracked dependency is deleted #20133

Closed

Handle deleted rebuild dependencies in CLI watch #20114

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Ensure `@tailwindcss/cli` recovers from a deleted transitive dependency#20137

Ensure `@tailwindcss/cli` recovers from a deleted transitive dependency#20137
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RobinMalfait commented Jun 1, 2026

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Confidence Score: 4/5

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