What causes "cannot create migration: %w" in hasura/graphql-engine?

Check the migrations directory is writable and the CLI is run from the project root

cannot create migration: %w

Error message

cannot create migration: %w

What it means

Returned by SquashCmd when creating the squashed migration files on disk fails after computing versions. The underlying createOptions.Create() error is wrapped with 'cannot create migration'.

Source

Thrown at cli/migrate/cmd/commands.go:260

	from uint64,
	to int64,
	version int64,
	name, directory string,
) (versions []int64, err error) {
	var op errors.Op = "cmd.SquashCmd"

	versions, upSql, downSql, err := m.Squash(from, to)
	if err != nil {
		return versions, errors.E(op, err)
	}

	createOptions := New(version, name, directory)
	createOptions.SQLUp = upSql
	createOptions.SQLDown = downSql

	err = createOptions.Create()
	if err != nil {
		return versions, errors.E(op, fmt.Errorf("cannot create migration: %w", err))
	}

	return versions, nil
}

func GotoVersionCmd(m *migrate.Migrate, gotoVersion int64) error {
	var op errors.Op = "cmd.GotoVersionCmd"

	err := m.GotoVersion(gotoVersion)
	if err != nil {
		return errors.E(op, err)
	}

	return nil
}

View on GitHub (pinned to 724551b9ae)

Solutions

Check the migrations directory is writable and the CLI is run from the project root
Remove or rename leftover partially-created migration files from a failed squash, then retry
Verify the --name flag produces a valid file name
Re-run squash; versions are recomputed each attempt

Defensive patterns

Strategy: validation

Validate before calling

info, err := os.Stat(migrationsDir)
if err != nil || !info.IsDir() { return fmt.Errorf("migrations dir missing") }
if err := os.WriteFile(filepath.Join(migrationsDir, ".probe"), nil, 0644); err != nil { return err }
os.Remove(filepath.Join(migrationsDir, ".probe"))

Prevention

Run squash from the project root with a writable migrations directory
Clean up partial files after failed squash attempts before retrying

When it happens

Trigger: Running `hasura migrate squash` where writing the new migration files fails: unwritable migrations directory, a file with the same timestamp/version already exists, or invalid migration name.

Common situations: Read-only checkout, incorrect --name, running squash from the wrong directory, or leftover files from a previous squash attempt with the same version timestamp.

Related errors

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/940a92af9682ee69. Report an issue: GitHub.