fix(oxlint/lsp): use blocking stdio in Oxlint by overlookmotel · Pull Request #19292 · oxc-project/oxc

overlookmotel · 2026-02-11T23:43:45Z

Fixes #19265.

It looks like the cause of the "Resource temporarily unavailable" errors was that NodeJS sets stdin/stdout into non-blocking mode when run from a non-TTY. In non-blocking mode it's possible to fill the stdin / stdout buffers faster than they're consumed, which leads to the error.

The language server communicates with oxlint via piped stdin/stdout, and can exchange a lot of data via these channels.

Solution is to switch to blocking stdio when it's detected that Oxlint is not being run from a TTY.

Oxfmt also ran into the same problem, and has a similar workaround:

oxc/apps/oxfmt/src-js/cli.ts

Lines 16 to 23 in 87a6724

    
           // Node.js sets non-TTY `stdio` to non-blocking mode, 
        
           // which causes `WouldBlock` errors in Rust when writing large output with `--stdin-filepath`. 
        
           // https://github.com/oxc-project/oxc/issues/17939 (issue was on macOS) 
        
           // 
        
           // As a workaround, if used with pipe, set blocking mode before calling NAPI bindings. 
        
           // See: https://github.com/napi-rs/napi-rs/issues/1630 
        
           // @ts-expect-error: `_handle` is an internal API 
        
           if (!process.stdout.isTTY) process.stdout._handle?.setBlocking?.(true);

In the case of Oxlint-language server, traffic on both stdin and stdout can be voluminous, so I've made both channels blocking (where Oxfmt only makes stdout blocking). I don't know if this is entirely necessary, but it seems better to err on the safe side.

I've tested this PR with both the plugins which were confirmed to cause the problem in #19265. Both now work, and both enabled at the same time also works.

References:

Credit to @camc314 for joining the dots and figuring out that this weird problem was connected to this.

overlookmotel · 2026-02-11T23:43:59Z

fix(oxlint/lsp): use blocking stdio in Oxlint #19292 👈 (View in Graphite)
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Copilot

Pull request overview

This PR fixes "Resource temporarily unavailable" errors in the Oxlint language server by setting stdin and stdout to blocking mode when running in non-TTY environments. Node.js sets non-TTY stdio to non-blocking mode by default, which can cause EAGAIN errors when large amounts of data are exchanged via pipes, particularly when loading large JavaScript plugins in the language server.

Changes:

Added blocking mode configuration for stdin/stdout in non-TTY environments before calling NAPI bindings
Applied similar workaround pattern already used in oxfmt to oxlint CLI
Sets both stdin and stdout to blocking (oxfmt only sets stdout) due to bidirectional high-volume communication in language server usage

Sysix

Enabled stylistic plugin with all its rules in the oxc project and tried with the debug and release build. Now it works 👍

overlookmotel · 2026-02-12T08:38:54Z

Enabled stylistic plugin with all its rules in the oxc project and tried with the debug and release build. Now it works 👍

Thanks for testing it so thoroughly.

What system were you testing it on? I've tested on MacOS. If you tested on Windows / Linux under WSL, that'd give us even more confidence that this is the definitive fix.

camc314 · 2026-02-12T09:09:53Z

Merge activity

Feb 12, 9:09 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 12, 9:09 AM UTC: camc314 added this pull request to the Graphite merge queue.
Feb 12, 9:19 AM UTC: Merged by the Graphite merge queue.

@camc314

Fixes #19265. It looks like the cause of the "Resource temporarily unavailable" errors was that NodeJS sets stdin/stdout into non-blocking mode when run from a non-TTY. In non-blocking mode it's possible to fill the stdin / stdout buffers faster than they're consumed, which leads to the error. The language server communicates with `oxlint` via piped stdin/stdout, and can exchange a lot of data via these channels. Solution is to switch to blocking stdio when it's detected that Oxlint is not being run from a TTY. Oxfmt also ran into the same problem, and has a similar workaround: https://github.com/oxc-project/oxc/blob/87a6724f167740ca116e73bf3f611d94ec7645e0/apps/oxfmt/src-js/cli.ts#L16-L23 In the case of Oxlint-language server, traffic on both stdin and stdout can be voluminous, so I've made both channels blocking (where Oxfmt only makes `stdout` blocking). I don't know if this is entirely necessary, but it seems better to err on the safe side. --- I've tested this PR with both the plugins which were confirmed to cause the problem in #19265. Both now work, and both enabled at the same time also works. --- References: * #17939 * napi-rs/napi-rs#1630 Credit to @camc314 for joining the dots and figuring out that this weird problem was connected to this.

# Oxlint ### 🚀 Features - ebb80b3 ast: Add `node_id` field to all AST struct nodes (#18138) (Boshen) - 2879fc5 linter: Implement fixer for unicorn/prefer-math-trunc (#19275) (camc314) - a204eda linter: Implement fixer for unicorn/no-typeof-undefined (#19274) (camc314) - ab46d9c linter: Implement typescript/class-literal-property-style (#19252) (Vincent R) - 1a61f58 linter: Implement typescript/no-invalid-void-type (#19242) (Vincent R) ### 🐛 Bug Fixes - 45adda2 oxlint/lsp: Use blocking stdio in Oxlint (#19292) (overlookmotel) - 05bc855 linter/import: Count unique module sources in max-dependencies (#19270) (camc314) - 8566b44 linter: Check for preceeding token in math trunc fixer (#19277) (camc314) - f16f2b6 linter/import-no-cycle: Avoid traversal-order false negatives with type-only edges (#19267) (camc314) - d4937e7 linter: Recognize module-scoped callback refs as stable in exhaustive-deps (#19220) (Sreetam Das) - 140c9bd linter: Detect fallthrough from `default` when it is not the last case (#19261) (Boshen) - 740a009 linter: Accept digits after 'use' in hook names (#19254) (Sreetam Das) - 31b562f linter: Update `import/no-named-as-default` to allow named import if equivalent to the default import (#19100) (connorshea) - 79c82cc linter: Avoid applying object-level docs to nested object methods in require-param (#19231) (camc314) ### ⚡ Performance - 5670291 linter/class-literal-property-style: Avoid unneeded string allocations (#19262) (camc314) # Oxfmt ### 🚀 Features - ebb80b3 ast: Add `node_id` field to all AST struct nodes (#18138) (Boshen) ### 🐛 Bug Fixes - 1957908 formatter: Avoid unnecessary parentheses for string literal in labeled statement (#19272) (Dunqing) Co-authored-by: camc314 <[email protected]>

@camc314

Fixes oxc-project#19265. It looks like the cause of the "Resource temporarily unavailable" errors was that NodeJS sets stdin/stdout into non-blocking mode when run from a non-TTY. In non-blocking mode it's possible to fill the stdin / stdout buffers faster than they're consumed, which leads to the error. The language server communicates with `oxlint` via piped stdin/stdout, and can exchange a lot of data via these channels. Solution is to switch to blocking stdio when it's detected that Oxlint is not being run from a TTY. Oxfmt also ran into the same problem, and has a similar workaround: https://github.com/oxc-project/oxc/blob/87a6724f167740ca116e73bf3f611d94ec7645e0/apps/oxfmt/src-js/cli.ts#L16-L23 In the case of Oxlint-language server, traffic on both stdin and stdout can be voluminous, so I've made both channels blocking (where Oxfmt only makes `stdout` blocking). I don't know if this is entirely necessary, but it seems better to err on the safe side. --- I've tested this PR with both the plugins which were confirmed to cause the problem in oxc-project#19265. Both now work, and both enabled at the same time also works. --- References: * oxc-project#17939 * napi-rs/napi-rs#1630 Credit to @camc314 for joining the dots and figuring out that this weird problem was connected to this.

@camc314

Fixes oxc-project#19265. It looks like the cause of the "Resource temporarily unavailable" errors was that NodeJS sets stdin/stdout into non-blocking mode when run from a non-TTY. In non-blocking mode it's possible to fill the stdin / stdout buffers faster than they're consumed, which leads to the error. The language server communicates with `oxlint` via piped stdin/stdout, and can exchange a lot of data via these channels. Solution is to switch to blocking stdio when it's detected that Oxlint is not being run from a TTY. Oxfmt also ran into the same problem, and has a similar workaround: https://github.com/oxc-project/oxc/blob/87a6724f167740ca116e73bf3f611d94ec7645e0/apps/oxfmt/src-js/cli.ts#L16-L23 In the case of Oxlint-language server, traffic on both stdin and stdout can be voluminous, so I've made both channels blocking (where Oxfmt only makes `stdout` blocking). I don't know if this is entirely necessary, but it seems better to err on the safe side. --- I've tested this PR with both the plugins which were confirmed to cause the problem in oxc-project#19265. Both now work, and both enabled at the same time also works. --- References: * oxc-project#17939 * napi-rs/napi-rs#1630 Credit to @camc314 for joining the dots and figuring out that this weird problem was connected to this.

# Oxlint ### 🚀 Features - ebb80b3 ast: Add `node_id` field to all AST struct nodes (oxc-project#18138) (Boshen) - 2879fc5 linter: Implement fixer for unicorn/prefer-math-trunc (oxc-project#19275) (camc314) - a204eda linter: Implement fixer for unicorn/no-typeof-undefined (oxc-project#19274) (camc314) - ab46d9c linter: Implement typescript/class-literal-property-style (oxc-project#19252) (Vincent R) - 1a61f58 linter: Implement typescript/no-invalid-void-type (oxc-project#19242) (Vincent R) ### 🐛 Bug Fixes - 45adda2 oxlint/lsp: Use blocking stdio in Oxlint (oxc-project#19292) (overlookmotel) - 05bc855 linter/import: Count unique module sources in max-dependencies (oxc-project#19270) (camc314) - 8566b44 linter: Check for preceeding token in math trunc fixer (oxc-project#19277) (camc314) - f16f2b6 linter/import-no-cycle: Avoid traversal-order false negatives with type-only edges (oxc-project#19267) (camc314) - d4937e7 linter: Recognize module-scoped callback refs as stable in exhaustive-deps (oxc-project#19220) (Sreetam Das) - 140c9bd linter: Detect fallthrough from `default` when it is not the last case (oxc-project#19261) (Boshen) - 740a009 linter: Accept digits after 'use' in hook names (oxc-project#19254) (Sreetam Das) - 31b562f linter: Update `import/no-named-as-default` to allow named import if equivalent to the default import (oxc-project#19100) (connorshea) - 79c82cc linter: Avoid applying object-level docs to nested object methods in require-param (oxc-project#19231) (camc314) ### ⚡ Performance - 5670291 linter/class-literal-property-style: Avoid unneeded string allocations (oxc-project#19262) (camc314) # Oxfmt ### 🚀 Features - ebb80b3 ast: Add `node_id` field to all AST struct nodes (oxc-project#18138) (Boshen) ### 🐛 Bug Fixes - 1957908 formatter: Avoid unnecessary parentheses for string literal in labeled statement (oxc-project#19272) (Dunqing) Co-authored-by: camc314 <[email protected]>

github-actions bot added A-linter Area - Linter A-cli Area - CLI A-linter-plugins Area - Linter JS plugins C-bug Category - Bug labels Feb 11, 2026

overlookmotel marked this pull request as ready for review February 11, 2026 23:57

overlookmotel requested a review from camc314 as a code owner February 11, 2026 23:57

Copilot AI review requested due to automatic review settings February 11, 2026 23:57

Copilot started reviewing on behalf of overlookmotel February 11, 2026 23:57 View session

overlookmotel mentioned this pull request Feb 11, 2026

feat(oxlint/lsp): option to enable JS plugins #19290

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overlookmotel requested a review from Sysix February 11, 2026 23:59

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graphite-app bot force-pushed the om/02-11-fix_oxlint_lsp_use_blocking_stdio_in_oxlint branch from 3371681 to 45adda2 Compare February 12, 2026 09:13

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Boshen mentioned this pull request Feb 12, 2026

release(apps): oxlint v1.47.0 && oxfmt v0.32.0 #19315

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This was referenced Feb 12, 2026

language server: JS Plugins support #18662

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linter: panic if stdout is large and not TTY #19124

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camc314 mentioned this pull request Feb 19, 2026

fix(diagnostics): handle WouldBlock errors when writing to stdout #17238

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fix(oxlint/lsp): use blocking stdio in Oxlint#19292

fix(oxlint/lsp): use blocking stdio in Oxlint#19292
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	// Node.js sets non-TTY `stdio` to non-blocking mode,
	// which causes `WouldBlock` errors in Rust when writing large output with `--stdin-filepath`.
	// https://github.com/oxc-project/oxc/issues/17939 (issue was on macOS)
	//
	// As a workaround, if used with pipe, set blocking mode before calling NAPI bindings.
	// See: https://github.com/napi-rs/napi-rs/issues/1630
	// @ts-expect-error: `_handle` is an internal API
	if (!process.stdout.isTTY) process.stdout._handle?.setBlocking?.(true);

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