Jj Conflicts

Jj Conflict Resolution

This skill helps you identify and resolve conflicts in jj repositories, with special emphasis on safely using jj restore with path specifications.

Understanding Jj Conflicts

How Jj Differs from Git

• Git: Conflicts block operations; you must resolve before continuing
• Jj: Conflicts are stored in commits; you can continue working and resolve later

When jj encounters a conflict, it:

1. Marks the commit with a conflict indicator (× in jj log)
2. Stores conflict markers in the affected files
3. Allows you to continue working on descendants

Types of Conflicts

"2-sided conflict": Two versions of the same content that can't be automatically merged

"2-sided conflict including 1 deletion": One side deleted a file/content, the other modified it

• Common when adding files to .gitignore after they were already tracked
• One of the most frequent conflict scenarios

Identifying Conflicts

Find All Conflicted Commits

jj log -r 'conflicts()'

This shows all commits with unresolved conflicts. Look for the × marker.

Check Current Status

jj status

If you're in a conflicted commit, this will show:

Warning: There are unresolved conflicts at these paths:
.obsidian/workspace.json    2-sided conflict including 1 deletion

Inspect Specific Conflict

jj edit <conflicted-commit-id>
jj diff

Resolution Strategies

Strategy A: Using jj resolve (Recommended for Most Cases)

The jj resolve command is purpose-built for conflict resolution:

# Navigate to conflicted commit
jj edit <commit-id>

# List all conflicts
jj resolve --list

# Accept parent's version (side 1) - "ours"
jj resolve --tool :ours <path>

# Accept child's version (side 2) - "theirs"
jj resolve --tool :theirs <path>

# Use interactive merge tool (if configured)
jj resolve <path>

When to use:

• Most conflict scenarios
• When you want semantic clarity (:ours vs :theirs)
• When working with merge tools

Strategy B: Using jj restore (Safe When Paths Specified)

The jj restore command can restore files from any commit:

# Navigate to conflicted commit
jj edit <commit-id>

# Restore SPECIFIC path from parent
jj restore --from @- <path>

When to use:

• Accepting parent's version for specific files
• When you want more control over the source (--from can be any revision)
• For deletion conflicts (equivalent to :ours in resolve)

⚠️ CRITICAL: The Path Argument

This is the most important safety rule when using jj restore:

# ❌ DANGEROUS - Restores ALL files from parent
#    This will LOSE ALL CHANGES in the current commit!
jj restore --from @-

# ✅ SAFE - Restores ONLY the specified path
#    All other changes in the commit are preserved
jj restore --from @- .obsidian/
jj restore --from @- src/config.rs

Why this matters:

• Without a path argument, jj restore operates on ALL files
• With a path argument, it operates ONLY on that specific path
• The difference between preserving your work and losing it entirely

Strategy C: Manual Editing

For complex conflicts, you can edit the conflict markers directly:

jj edit <commit-id>
# Edit files with conflict markers
# Remove markers and keep desired content
jj diff  # Verify your resolution

Conflict markers look like:

<<<<<<<
Content from side 1 (parent)
%%%%%%%
Common ancestor content
+++++++
Content from side 2 (child)
>>>>>>>

Strategy D: New Commit Then Squash (Jj's Recommended Pattern)

For complex resolutions, jj recommends creating a resolution commit:

# Create new commit on top of conflicted one
jj new <conflicted-commit-id>

# Resolve using any method above
jj resolve --tool :ours <path>

# Review the resolution
jj diff

# Squash resolution back into parent
jj squash

Benefits:

• Separates resolution from original changes
• Easy to review resolution before committing
• Can undo resolution easily

Common Conflict Scenarios

Scenario 1: Parent Deleted, Child Modified

Situation: Parent commit deleted files (e.g., added to .gitignore), but child commits still have changes to those files.

Example: You added .obsidian/ to .gitignore and untracked it in commit oo, but 13 descendant commits still had .obsidian/ changes.

Conflict message:

.obsidian/workspace.json    2-sided conflict including 1 deletion

Resolution: Accept the deletion by restoring from parent

# Method 1: Using jj resolve (more semantic)
jj edit <conflicted-commit>
jj resolve --tool :ours .obsidian/

# Method 2: Using jj restore (equally correct)
jj edit <conflicted-commit>
jj restore --from @- .obsidian/

For multiple commits:

# Process each conflicted commit
for commit in $(jj log -r 'conflicts()' --no-graph -T 'change_id.short(4)'); do
  jj edit "$commit"
  jj restore --from @- .obsidian/
done

Scenario 2: Both Sides Modified Same Content

Situation: Both parent and child modified the same lines in a file.

Resolution options:

1. Accept one side: jj resolve --tool :ours or :theirs
2. Merge manually: Edit conflict markers
3. Use merge tool: jj resolve <path> (if configured)

Scenario 3: Rename Conflicts

Situation: One side renamed a file, the other modified it.

Resolution: Choose which version to keep, potentially applying changes from other side manually.

Key Differences: jj restore vs jj resolve

Both are correct for accepting deletions, but resolve is more semantically clear.

Safety Checklist

Before resolving conflicts:

• ✅ Always specify path arguments when using jj restore --from
• ✅ Use jj diff to verify changes before and after resolution
• ✅ Test resolution with one commit before batch processing
• ✅ Check jj status to confirm conflict is resolved
• ❌ Never use jj restore --from @- without paths unless you intend to reset entire commit

Real-World Example: Untracking Previously-Committed Files

This documents a real scenario that illustrates the critical importance of path specification:

The Situation

1. You added .obsidian/ to .gitignore in commit oo
2. You untracked .obsidian/ files in that commit: jj file untrack .obsidian/
3. 13 descendant commits still contained .obsidian/ changes
4. After rebasing: jj rebase -r 'oo..@' -d oo
5. Result: All 13 descendant commits now have conflicts

The Conflicts

Each conflict shows:

.obsidian/workspace.json    2-sided conflict including 1 deletion

This means:

• Parent (commit oo): Deleted .obsidian/ files
• Child commits: Still have changes to .obsidian/ files

The Wrong Approach (What NOT to Do)

# ❌ WRONG - This was tried first
jj edit <commit-id>
jj restore --from @-  # No path specified!

# Result: ALL files restored from parent
# - All task files: DELETED
- All document changes: LOST
# - Only .obsidian/ should have been affected, but EVERYTHING was reset

Why this failed: Without a path argument, jj restore --from @- restores every file from the parent, effectively undoing all changes in the commit.

The Correct Solution

# ✅ CORRECT - Specify the path
jj edit <commit-id>
jj restore --from @- .obsidian/  # Path specified!

# Result: Only .obsidian/ restored from parent
# - Task files: PRESERVED ✓
# - Document changes: PRESERVED ✓
# - .obsidian/ conflicts: RESOLVED ✓

Or using jj resolve (more semantic):

jj edit <commit-id>
jj resolve --tool :ours .obsidian/

Processing All Conflicts

# Get list of conflicted commits
jj log -r 'conflicts()'

# Process each one with PATHS SPECIFIED
for commit in oymp zzyv knzl xlxr lutt xznz uvnk zosw vzxv utmq xtsk qvot pqnr; do
  echo "Resolving $commit"
  jj edit "$commit"
  jj restore --from @- .obsidian/  # ← The critical path argument
done

# Verify all conflicts resolved
jj log -r 'conflicts()'  # Should return empty

Key Takeaway

The difference between these two commands is losing all your work vs safely resolving conflicts:

jj restore --from @-             # ← Danger: ALL files
jj restore --from @- .obsidian/  # ← Safe: ONLY specified path

Always specify the path when resolving conflicts with jj restore.

Quick Reference

Find conflicts

jj log -r 'conflicts()'
jj status

Resolve with jj resolve

jj edit <commit-id>
jj resolve --tool :ours <path>    # Accept parent's version
jj resolve --tool :theirs <path>  # Accept child's version

Resolve with jj restore (MUST SPECIFY PATH)

jj edit <commit-id>
jj restore --from @- <path>  # Accept parent's version for PATH ONLY

Verify resolution

jj diff
jj status
jj log -r 'conflicts()'  # Should not include current commit

Integration with Other Workflows

After Rebase

Rebasing often creates conflicts:

jj rebase -r <commits> -d <destination>
# Check for new conflicts
jj log -r 'conflicts()'
# Resolve as needed

Before Push

Always resolve conflicts before pushing:

# Check for unresolved conflicts
jj log -r 'conflicts() & mine()'

# If any found, resolve them first
# Then proceed with push

With jj-spr

Conflicts can appear when updating stacked PRs:

jj rebase -d main
# Resolve any conflicts
jj restore --from @- <conflicted-path>
# Update PRs
jj spr update

When to Use This Skill

Invoke this skill when you encounter:

• "There are unresolved conflicts at these paths"
• × markers in jj log output
• "2-sided conflict" messages
• Questions about using jj restore safely
• Need to accept parent's or child's version in conflicts
• Rebase operations that create conflicts
• Files that were added to .gitignore after being tracked