chore: import upstream snapshot with attribution

cli-tool/components/skills/development/error-resolver/patterns/git.md

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+# Git Error Patterns
+
+Common Git errors with diagnosis and solutions.
+
+## Push/Pull Errors
+
+### Failed to push: rejected
+
+```
+! [rejected]        main -> main (non-fast-forward)
+error: failed to push some refs to 'origin'
+```
+
+**Causes**:
+1. Remote has commits you don't have locally
+2. Force push required (history rewritten)
+3. Branch protection rules
+
+**Solutions**:
+```bash
+# Option 1: Pull and merge first (safest)
+git pull origin main
+git push origin main
+
+# Option 2: Pull with rebase
+git pull --rebase origin main
+git push origin main
+
+# Option 3: Force push (CAREFUL - overwrites remote)
+# Only if you intentionally rewrote history
+git push --force-with-lease origin main
+```
+
+---
+
+### Remote contains work you do not have locally
+
+```
+hint: Updates were rejected because the remote contains work that you do not have locally.
+```
+
+**Same as above** - pull first, then push.
+
+```bash
+# Standard workflow
+git fetch origin
+git merge origin/main  # Or: git rebase origin/main
+git push
+```
+
+---
+
+### Permission denied (publickey)
+
+```
+Permission denied (publickey).
+fatal: Could not read from remote repository.
+```
+
+**Causes**:
+1. SSH key not added to agent
+2. SSH key not added to GitHub/GitLab
+3. Wrong SSH key
+4. Using HTTPS URL instead of SSH
+
+**Diagnosis**:
+```bash
+# Test SSH connection
+ssh -T git@github.com
+ssh -vT git@github.com  # Verbose for debugging
+
+# Check loaded keys
+ssh-add -l
+```
+
+**Solutions**:
+```bash
+# Add SSH key to agent
+eval "$(ssh-agent -s)"
+ssh-add ~/.ssh/id_ed25519  # Or your key file
+
+# Generate new key if needed
+ssh-keygen -t ed25519 -C "your@email.com"
+
+# Copy public key to GitHub/GitLab
+cat ~/.ssh/id_ed25519.pub
+# Then add in GitHub Settings -> SSH Keys
+
+# Or use HTTPS instead of SSH
+git remote set-url origin https://github.com/user/repo.git
+```
+
+---
+
+### Authentication failed
+
+```
+remote: Invalid username or password.
+fatal: Authentication failed for 'https://github.com/...'
+```
+
+**Causes**:
+1. Wrong credentials
+2. Password auth disabled (GitHub)
+3. Token expired
+
+**Solutions**:
+```bash
+# Use Personal Access Token instead of password
+# Generate at: GitHub -> Settings -> Developer settings -> Personal access tokens
+
+# Update stored credentials
+git credential reject
+protocol=https
+host=github.com
+# Press Enter twice
+
+# Or use credential helper
+git config --global credential.helper cache
+git config --global credential.helper 'cache --timeout=3600'
+
+# Or switch to SSH
+git remote set-url origin git@github.com:user/repo.git
+```
+
+---
+
+## Merge Conflicts
+
+### Automatic merge failed
+
+```
+CONFLICT (content): Merge conflict in file.js
+Automatic merge failed; fix conflicts and then commit the result.
+```
+
+**Resolution Workflow**:
+```bash
+# 1. See conflicting files
+git status
+
+# 2. Open file and look for conflict markers
+<<<<<<< HEAD
+your changes
+=======
+their changes
+>>>>>>> branch-name
+
+# 3. Edit file to resolve (remove markers, keep desired code)
+
+# 4. Stage resolved files
+git add file.js
+
+# 5. Complete merge
+git commit
+# Or if rebasing: git rebase --continue
+```
+
+**Tools**:
+```bash
+# Use merge tool
+git mergetool
+
+# Configure VS Code as merge tool
+git config --global merge.tool vscode
+git config --global mergetool.vscode.cmd 'code --wait $MERGED'
+```
+
+**Abort if needed**:
+```bash
+git merge --abort
+# Or
+git rebase --abort
+```
+
+---
+
+### Cannot pull with rebase: unstaged changes
+
+```
+error: cannot pull with rebase: You have unstaged changes.
+```
+
+**Solutions**:
+```bash
+# Option 1: Stash changes
+git stash
+git pull --rebase
+git stash pop
+
+# Option 2: Commit changes first
+git add .
+git commit -m "WIP"
+git pull --rebase
+
+# Option 3: Discard changes (CAREFUL)
+git checkout -- .
+git pull --rebase
+```
+
+---
+
+## Checkout/Switch Errors
+
+### Cannot checkout: local changes would be overwritten
+
+```
+error: Your local changes to the following files would be overwritten by checkout
+```
+
+**Solutions**:
+```bash
+# Option 1: Stash changes
+git stash
+git checkout other-branch
+git stash pop  # To get changes back
+
+# Option 2: Commit changes
+git add .
+git commit -m "WIP"
+git checkout other-branch
+
+# Option 3: Discard changes (CAREFUL)
+git checkout -- file.js      # Single file
+git checkout -- .            # All files
+git reset --hard             # Everything including staged
+```
+
+---
+
+### Pathspec did not match any file
+
+```
+error: pathspec 'branch-name' did not match any file(s) known to git
+```
+
+**Causes**:
+1. Branch doesn't exist
+2. Typo in branch name
+3. Remote branch not fetched
+
+**Solutions**:
+```bash
+# List all branches
+git branch -a
+
+# Fetch remote branches
+git fetch origin
+
+# Checkout remote branch
+git checkout -b branch-name origin/branch-name
+# Or (newer Git)
+git switch branch-name
+```
+
+---
+
+## Reset/Revert Errors
+
+### HEAD detached
+
+```
+You are in 'detached HEAD' state.
+```
+
+**What it means**: You checked out a commit, not a branch.
+
+**Solutions**:
+```bash
+# Go back to branch
+git checkout main
+
+# Create new branch from current state
+git checkout -b new-branch-name
+
+# See where HEAD is
+git log --oneline -1
+```
+
+---
+
+### Cannot do soft reset with paths
+
+```
+fatal: Cannot do soft reset with paths.
+```
+
+**Solution**: Use different command:
+```bash
+# To unstage file
+git restore --staged file.js
+# Or older Git:
+git reset HEAD file.js
+```
+
+---
+
+### Refusing to reset in dirty worktree
+
+```
+fatal: Failed to resolve 'HEAD~1' as a valid ref.
+```
+
+**Solution**:
+```bash
+# Stash changes first
+git stash
+git reset --hard HEAD~1
+git stash pop
+```
+
+---
+
+## Stash Errors
+
+### No stash entries found
+
+```
+No stash entries found.
+```
+
+**Check stashes**:
+```bash
+# List all stashes
+git stash list
+
+# If empty, nothing was stashed
+```
+
+---
+
+### Conflict when applying stash
+
+```
+CONFLICT (content): Merge conflict in file.js
+```
+
+**Solutions**:
+```bash
+# Resolve conflicts manually (same as merge conflicts)
+# Then either:
+git stash drop  # Remove stash after resolving
+
+# Or if you want to keep stash:
+# Just resolve conflicts, add, and commit
+```
+
+---
+
+## Rebase Errors
+
+### Cannot rebase: uncommitted changes
+
+```
+error: cannot rebase: You have unstaged changes.
+```
+
+**Solution**:
+```bash
+git stash
+git rebase origin/main
+git stash pop
+```
+
+---
+
+### Rebase conflict
+
+```
+CONFLICT (content): Merge conflict in file.js
+error: could not apply abc1234... commit message
+```
+
+**Resolution**:
+```bash
+# 1. Fix conflicts in files
+
+# 2. Stage resolved files
+git add file.js
+
+# 3. Continue rebase
+git rebase --continue
+
+# Or abort entire rebase
+git rebase --abort
+
+# Skip this commit (lose its changes)
+git rebase --skip
+```
+
+---
+
+## Submodule Errors
+
+### Submodule not initialized
+
+```
+fatal: no submodule mapping found in .gitmodules for path 'submodule-path'
+```
+
+**Solutions**:
+```bash
+# Initialize submodules
+git submodule init
+git submodule update
+
+# Or clone with submodules
+git clone --recurse-submodules repo-url
+
+# Update existing clone
+git submodule update --init --recursive
+```
+
+---
+
+### Submodule HEAD detached
+
+```
+HEAD detached at abc1234
+```
+
+**Solution**:
+```bash
+cd submodule-path
+git checkout main  # Or desired branch
+cd ..
+git add submodule-path
+git commit -m "Update submodule to main"
+```
+
+---
+
+## LFS Errors
+
+### File exceeds GitHub file size limit
+
+```
+remote: error: File large-file.zip is 150.00 MB; this exceeds GitHub's file size limit of 100.00 MB
+```
+
+**Solutions**:
+```bash
+# Install Git LFS
+brew install git-lfs  # macOS
+git lfs install
+
+# Track large files
+git lfs track "*.zip"
+git lfs track "*.psd"
+git add .gitattributes
+
+# If already committed, need to rewrite history
+git filter-branch --tree-filter 'git lfs track "*.zip"' HEAD
+# Or use BFG Repo Cleaner
+```
+
+---
+
+### LFS objects missing
+
+```
+Encountered 1 file that should have been a pointer, but wasn't
+```
+
+**Solutions**:
+```bash
+# Fetch LFS objects
+git lfs fetch --all
+
+# Or pull LFS objects
+git lfs pull
+
+# Migrate existing files to LFS
+git lfs migrate import --include="*.psd"
+```
+
+---
+
+## Configuration Errors
+
+### Author identity unknown
+
+```
+Author identity unknown
+Please tell me who you are.
+```
+
+**Solution**:
+```bash
+git config --global user.email "you@example.com"
+git config --global user.name "Your Name"
+```
+
+---
+
+### Unsafe repository
+
+```
+fatal: detected dubious ownership in repository
+```
+
+**Causes**: Repository owned by different user (common in Docker/WSL).
+
+**Solution**:
+```bash
+# Add exception for this repo
+git config --global --add safe.directory /path/to/repo
+
+# Or for all repos (less secure)
+git config --global --add safe.directory '*'
+```
+
+---
+
+## Quick Reference Table
+
+| Error | Category | Quick Fix |
+|-------|----------|-----------|
+| Push rejected | Push | `git pull --rebase` then push |
+| Permission denied | Auth | Check SSH key: `ssh-add -l` |
+| Auth failed | Auth | Use Personal Access Token |
+| Merge conflict | Merge | Edit file, remove markers, `git add` |
+| Unstaged changes | Checkout | `git stash` first |
+| Pathspec not found | Branch | `git fetch` then checkout |
+| HEAD detached | Branch | `git checkout main` |
+| No stash entries | Stash | Nothing was stashed |
+| Rebase conflict | Rebase | Fix conflict, `git rebase --continue` |
+| File too large | LFS | Use Git LFS for large files |
+| Identity unknown | Config | Set user.email and user.name |