From 2822d24fc1ac3a49db1870c900a3eebf626bfc90 Mon Sep 17 00:00:00 2001
From: Toshihiko SHIMOKAWA <toshi@smkwlab.net>
Date: Mon, 3 Nov 2025 22:13:35 +0900
Subject: [PATCH 1/2] Document auto-skip build feature in CLAUDE.md

Add comprehensive documentation for CI/CD workflow's intelligent build
skipping feature, including:
- Automatic detection logic
- Commit message tag usage
- Examples and benefits
- Default behavior for PRs and main branch
---
 CLAUDE.md | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/CLAUDE.md b/CLAUDE.md
index 9f5246b..364509c 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -37,6 +37,73 @@ docker build -t atcoder-container:lite -f Dockerfile.lite .
 docker build -t atcoder-container:2025 .
 ```
 
+## CI/CD Workflow and Auto-Skip Build Feature
+
+The repository uses GitHub Actions workflow (`.github/workflows/build-staged.yml`) with intelligent build skipping to save time and resources.
+
+### Automatic Build Skipping
+
+The workflow automatically detects when only documentation files are changed and skips the build:
+
+**Files that trigger auto-skip:**
+- `*.md`, `*.txt` (documentation files)
+- `LICENSE`, `.gitignore`
+
+**When builds are always triggered:**
+- Any Dockerfile changes
+- Source code changes (Python, Java, Ruby, etc.)
+- Build script changes
+- toml configuration changes
+
+### Commit Message Tags (Manual Override)
+
+You can explicitly control build behavior using commit message tags. Tags take priority over automatic detection:
+
+- **`[skip-build]`**: Force skip all builds
+  - Use for: Documentation-only changes, README updates
+  - Example: `git commit -m "Update README [skip-build]"`
+
+- **`[build-lite]`**: Build only Lite version (both architectures)
+  - Use for: Changes affecting only lite version
+  - Builds: `atcoder-lite:2025` for linux/amd64 and linux/arm64
+
+- **`[build-full]`**: Build only Full version
+  - Use for: Changes to ML libraries or full-only features
+  - Builds: `atcoder-full:2025` for linux/amd64 (default platform)
+
+- **`[build-all]`**: Build both versions (both architectures)
+  - Use for: Core changes affecting both versions
+  - Builds: Both `atcoder-lite:2025` and `atcoder-full:2025` for linux/amd64 and linux/arm64
+
+### Default Behavior
+
+- **Pull Requests**: Automatically build Full version on x86_64 to catch issues early
+- **Main branch commits**: Follow automatic detection or tag-based control
+- **Manual workflow dispatch**: Choose build variant via GitHub Actions UI
+
+### Examples
+
+```bash
+# Documentation update - auto-skips build
+git commit -m "Update installation instructions in README.md"
+
+# Force build even for docs
+git commit -m "Update README with new feature [build-all]"
+
+# Skip build explicitly
+git commit -m "Fix typo in comments [skip-build]"
+
+# Build only lite version
+git commit -m "Update competitive programming libraries [build-lite]"
+```
+
+### Benefits
+
+- **Time savings**: README updates complete in seconds instead of 1-2 hours
+- **Resource efficiency**: Reduces unnecessary CI/CD usage
+- **Flexibility**: Manual override available when needed
+- **Safety**: PRs still validate with Full version build by default
+
 ## Supported Languages and Versions
 
 The container includes the following languages (versions as of January 2025):

From bf169779b2103b64fad63b58d704a442e3b174c0 Mon Sep 17 00:00:00 2001
From: Toshihiko SHIMOKAWA <toshi@smkwlab.net>
Date: Mon, 3 Nov 2025 22:20:47 +0900
Subject: [PATCH 2/2] Fix architecture name consistency in CLAUDE.md

Fixes #76 - Use 'linux/amd64' consistently instead of 'x86_64' to
match the platform naming convention used throughout the documentation.
---
 CLAUDE.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CLAUDE.md b/CLAUDE.md
index 364509c..1c1db0a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -77,7 +77,7 @@ You can explicitly control build behavior using commit message tags. Tags take p
 
 ### Default Behavior
 
-- **Pull Requests**: Automatically build Full version on x86_64 to catch issues early
+- **Pull Requests**: Automatically build Full version on linux/amd64 to catch issues early
 - **Main branch commits**: Follow automatic detection or tag-based control
 - **Manual workflow dispatch**: Choose build variant via GitHub Actions UI