rspack-tracing

Name: rspack-tracing
Author: rstackjs

84stars1forks

How to install rspack-tracing?

rstackjs/agent-skills/rspack-tracing

$npx -y skills add rstackjs/agent-skills --skill rspack-tracing

Installs into the current project.

Summary

Comprehensive guide and toolkit for diagnosing Rspack build issues. Quickly identify where crashes/errors occur, or perform detailed performance profiling to resolve bottlenecks. Use when the user encounters build failures, slow builds, or wants to optimize Rspack performance.

Files · 1

View on GitHub

SKILL.md

1	# Rspack Tracing & Performance Profiling
2
3	## When to Use This Skill
4
5	Use this skill when you need to:
6
7	1. Diagnose why an Rspack build is slow.
8	2. Understand which plugins or loaders are taking the most time.
9	3. Analyze a user-provided Rspack trace file.
10	4. Guide a user to capture a performance profile.
11
12	## Workflow
13
14	### 1. Capture a Trace
15
16	First, ask the user to run their build with tracing enabled.
17
18	```bash
19	# Set environment variables for logging to a file
20	RSPACK_PROFILE=TRACE RSPACK_TRACE_LAYER=logger RSPACK_TRACE_OUTPUT=./trace.json pnpm build
21	```
22
23	This will generate a trace file in a timestamped directory like `.rspack-profile-{timestamp}-{pid}/trace.json`.
24
25	See [references/tracing-guide.md](references/tracing-guide.md) for more details on configuration.
26
27	### 2. Quick Diagnosis for Crashes/Errors
28
29	If the user wants to identify which stage a crash or error occurred in, use `tail` to quickly view the last events without running the full analysis:
30
31	```bash
32	# Navigate to the generated profile directory
33	cd .rspack-profile-*/
34
35	# View the last 20 events to see where the build failed
36	tail -n 20 trace.json
37	```
38
39	The last events will show the span names and targets where the build stopped, helping to quickly pinpoint the problematic stage, plugin, or loader.
40
41	### 3. Full Performance Analysis
42
43	For detailed performance profiling (not just crash diagnosis), ask the user to run the bundled analysis script on the generated trace file.
44
45	```bash
46	# Navigate to the generated profile directory
47	cd .rspack-profile-*/
48
49	# Run the analysis script
50	node ${CLAUDE_PLUGIN_ROOT}/skills/tracing/scripts/analyze_trace.js trace.json
51	```
52
53	### 4. Interpret Results
54
55	Use the output from the script to identify bottlenecks.
56	Consult [references/bottlenecks.md](references/bottlenecks.md) to map span names to actionable fixes.
57
58	### 5. Locate Slow Plugins
59
60	Based on the "Top Slowest Hooks" from the analysis script:
61
62	1. Identify the Hook: Note the hook name (e.g., `hook:CompilationOptimizeChunks`).
63	2. Inspect Configuration: Read `rspack.config.js` or `rsbuild.config.ts`.
64	3. Map Hook to Plugin: Look for plugins and their sources that tap into that specific hook.
65	4. Output: Output the paths, lines and columns of the suspected plugin source code.
66
67	## Common Scenarios & Quick Fixes
68
69	- [Bottleneck Reference](references/bottlenecks.md): Mapping spans to concepts.
70	- [Tracing Guide](references/tracing-guide.md): Detailed usage of `RSPACK_PROFILE`.

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rspack-tracing

84stars1forks

View on GitHub

How to install rspack-tracing?

rstackjs/agent-skills/rspack-tracing

$npx -y skills add rstackjs/agent-skills --skill rspack-tracing

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Rspack Tracing & Performance Profiling
2
3	## When to Use This Skill
4
5	Use this skill when you need to:
6
7	1. Diagnose why an Rspack build is slow.
8	2. Understand which plugins or loaders are taking the most time.
9	3. Analyze a user-provided Rspack trace file.
10	4. Guide a user to capture a performance profile.
11
12	## Workflow
13
14	### 1. Capture a Trace
15
16	First, ask the user to run their build with tracing enabled.
17
18	```bash
19	# Set environment variables for logging to a file
20	RSPACK_PROFILE=TRACE RSPACK_TRACE_LAYER=logger RSPACK_TRACE_OUTPUT=./trace.json pnpm build
21	```
22
23	This will generate a trace file in a timestamped directory like `.rspack-profile-{timestamp}-{pid}/trace.json`.
24
25	See [references/tracing-guide.md](references/tracing-guide.md) for more details on configuration.
26
27	### 2. Quick Diagnosis for Crashes/Errors
28
29	If the user wants to identify which stage a crash or error occurred in, use `tail` to quickly view the last events without running the full analysis:
30
31	```bash
32	# Navigate to the generated profile directory
33	cd .rspack-profile-*/
34
35	# View the last 20 events to see where the build failed
36	tail -n 20 trace.json
37	```
38
39	The last events will show the span names and targets where the build stopped, helping to quickly pinpoint the problematic stage, plugin, or loader.
40
41	### 3. Full Performance Analysis
42
43	For detailed performance profiling (not just crash diagnosis), ask the user to run the bundled analysis script on the generated trace file.
44
45	```bash
46	# Navigate to the generated profile directory
47	cd .rspack-profile-*/
48
49	# Run the analysis script
50	node ${CLAUDE_PLUGIN_ROOT}/skills/tracing/scripts/analyze_trace.js trace.json
51	```
52
53	### 4. Interpret Results
54
55	Use the output from the script to identify bottlenecks.
56	Consult [references/bottlenecks.md](references/bottlenecks.md) to map span names to actionable fixes.
57
58	### 5. Locate Slow Plugins
59
60	Based on the "Top Slowest Hooks" from the analysis script:
61
62	1. Identify the Hook: Note the hook name (e.g., `hook:CompilationOptimizeChunks`).
63	2. Inspect Configuration: Read `rspack.config.js` or `rsbuild.config.ts`.
64	3. Map Hook to Plugin: Look for plugins and their sources that tap into that specific hook.
65	4. Output: Output the paths, lines and columns of the suspected plugin source code.
66
67	## Common Scenarios & Quick Fixes
68
69	- [Bottleneck Reference](references/bottlenecks.md): Mapping spans to concepts.
70	- [Tracing Guide](references/tracing-guide.md): Detailed usage of `RSPACK_PROFILE`.

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