dagger/dagger · error

parsing legacy module config %s: %w

Error message

parsing legacy module config %s: %w

What it means

Wraps a workspace.ParseLegacyModuleConfigTolerant failure (message in source reads 'parsing legacy module config') while reading a pre-workspace dagger.json from the caller's host during migration. The file was read successfully but its contents are not a valid legacy module config; the migration aborts rather than guessing.

Source

Thrown at core/schema/workspace_migrate.go:403

		configPath := filepath.Join(ws.HostPath(), filepath.FromSlash(cp.Path))
		configDir := filepath.Dir(configPath)
		hasWorkspaceConfig, err := workspaceMigrationHasExplicitConfigAncestor(workspaceCtx, statFS, ws.HostPath(), configDir)
		if err != nil {
			return nil, nil, err
		}
		if hasWorkspaceConfig {
			// FIXME(workspace-migrate): Match the top-level explicit-config rule
			// for now: pre-existing workspace configs own migration below them.
			continue
		}

		data, err := bk.ReadCallerHostFile(workspaceCtx, configPath)
		if err != nil {
			return nil, nil, fmt.Errorf("reading legacy module config %s: %w", cp.Path, err)
		}
		compatWorkspace, err := workspaceMigrationCompatWorkspaceForLegacyConfig(data, configPath)
		if err != nil {
			return nil, nil, fmt.Errorf("parsing legacy module config %s: %w", cp.Path, err)
		}
		if compatWorkspace == nil {
			continue
		}
		compatWorkspace.DiscoveredLocalModule = cp.DiscoveredLocalModule
		compatWorkspaces = append(compatWorkspaces, compatWorkspace)
	}
	return compatWorkspaces, discoveryWarnings, nil
}

// workspaceMigrationConfigPath is a legacy config selected for migration,
// tagged with whether it was reached by following a local module reference
// from the selected root config (rather than being the selection itself).
type workspaceMigrationConfigPath struct {
	Path                  string
	DiscoveredLocalModule bool
}

View on GitHub (pinned to 82ba2681db)

Solutions

1. Fix or remove the malformed legacy dagger.json named in the error
2. Ensure the file is valid JSON with the expected module fields

When it happens

Trigger: Thrown at core/schema/workspace_migrate.go:403 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of dagger/dagger@82ba2681db (2026-09-05). Data as JSON: /api/errors/f9593b2bed59701d. Report an issue: GitHub.