Django "Conflicting migrations detected" - Merge Branches

By Kaveh Alemi·Latchkey

Two migrations in the same app share the same parent, leaving the migration graph with more than one leaf. Django cannot pick a single linear path until you add a merge migration that joins them.

What this error means

migrate or makemigrations --check fails reporting conflicting migrations / multiple leaf nodes for an app. It appears after two branches each created a migration on top of the same previous one and both merged.

CommandError: Conflicting migrations detected; multiple leaf nodes in the
migration graph: (0007_a, 0007_b in orders).
To fix them run 'python manage.py makemigrations --merge'

Common causes

Two branches forked the same parent migration

Each branch ran makemigrations on top of, say, 0006, producing two 0007_* leaves. Merging both branches leaves the app with two leaf nodes.

No merge migration created

A fork is legitimate, but Django needs an explicit merge migration to rejoin the two leaves into a single linear head.

How to fix it

Create a merge migration

Let Django generate a migration that depends on both leaves, rejoining the graph.

python manage.py makemigrations --merge
git add orders/migrations/0008_merge_*.py

Or rebase one migration onto the other

1. Edit one branch’s migration dependencies to point at the other branch’s leaf.
2. This linearizes the graph into a single chain with one leaf.
3. Prefer the merge migration when both branches are already shared.

How to prevent it

• Run makemigrations --check in CI so multiple leaves are caught early.
• Rebase/merge migration branches before merging feature branches.
• Coordinate so two branches don’t fork the same parent migration unnoticed.

Frequently asked questions

Related guides

References

• GitHub Actions documentation