feat(core): add NX_BAIL environment variable

[jase88]

Current Behavior

The --nxBail / --nx-bail flag can only be set via the CLI:

nx run-many -t build --nxBail

There is no way to enable bail-on-first-failure through an environment variable. Users who want this behavior permanently (e.g., in CI) must always pass the flag explicitly in every command invocation.

Expected Behavior

The --nxBail / --nx-bail flag can now also be activated via the NX_BAIL environment variable:

NX_BAIL=true nx run-many -t build

This mirrors the pattern used by other Nx environment variables (e.g. NX_DEFAULT_OUTPUT_STYLE for --outputStyle)

Related Issue(s)

#26899

[netlify]

✅ Deploy Preview for nx-docs canceled.

Name	Link
🔨 Latest commit	eb5e527
🔍 Latest deploy log	https://app.netlify.com/projects/nx-docs/deploys/69d6b0eedf739a0007c8ca65

[netlify]

✅ Deploy Preview for nx-dev canceled.

Name	Link
🔨 Latest commit	45910f9
🔍 Latest deploy log	https://app.netlify.com/projects/nx-dev/deploys/69d6b0a6df739a0007c8c186

[nx-cloud]

View your CI Pipeline Execution ↗ for commit eb5e527

Command	Status	Duration	Result
nx affected --targets=lint,test,build,e2e,e2e-c...	✅ Succeeded	46m 51s	View ↗
nx run-many -t check-imports check-lock-files c...	✅ Succeeded	7s	View ↗
nx-cloud record -- pnpm nx conformance:check	✅ Succeeded	7s	View ↗
nx build workspace-plugin	✅ Succeeded	<1s	View ↗
nx-cloud record -- nx format:check	✅ Succeeded	1s	View ↗
nx-cloud record -- nx sync:check	✅ Succeeded	<1s	View ↗

---

☁️ Nx Cloud last updated this comment at 2026-04-15 21:41:33 UTC

[nx-cloud]

Important

At least one additional CI pipeline execution has run since the conclusion below was written and it may no longer be applicable.

Nx Cloud is proposing a fix for your failed CI:

We removed the default: false from the nxBail option so that yargs leaves the value as undefined when no CLI flag is passed, allowing the middleware's === undefined check to correctly detect the absence of an explicit argument. Without this change, yargs would always assign false before the middleware ran, making the NX_BAIL environment variable completely ineffective. This fix ensures NX_BAIL=true activates bail behavior while explicit CLI flags continue to take precedence.

Warning

❌ We could not verify this fix.

Suggested Fix changes

diff --git a/packages/nx/src/command-line/yargs-utils/shared-options.ts b/packages/nx/src/command-line/yargs-utils/shared-options.ts
index d6bb979600..f72e25b92b 100644
--- a/packages/nx/src/command-line/yargs-utils/shared-options.ts
+++ b/packages/nx/src/command-line/yargs-utils/shared-options.ts
@@ -113,11 +113,10 @@ export function withRunOptions<T>(yargs: Argv<T>): Argv<T & RunOptions> {
     .option('nxBail', {
       describe: 'Stop command execution after the first failed task.',
       type: 'boolean',
-      default: false,
     })
     .middleware((args) => {
-      if (args.nxBail === undefined && process.env.NX_BAIL === 'true') {
-        args.nxBail = true;
+      if (args.nxBail === undefined) {
+        args.nxBail = process.env.NX_BAIL === 'true';
       }
     })
     .option('nxIgnoreCycles', {

🔔 Heads up, your workspace has pending recommendations ↗ to auto-apply fixes for similar failures.

Because this branch comes from a fork, it is not possible for us to apply fixes directly, but you can apply the changes locally using the available options below.

Apply changes locally with:

npx nx-cloud apply-locally Q6L5-9cjg

Apply fix locally with your editor ↗   View interactive diff ↗

_{🎓 Learn more about Self-Healing CI on nx.dev}

[github-actions]

This pull request has already been merged/closed. If you experience issues related to these changes, please open a new issue referencing this pull request.