dagger/dagger · error

apply changes to workspace root: %w

Error message

apply changes to workspace root: %w

What it means

This error wraps a failure of the dagql Select call that applies a changeset to the workspace root directory via Directory.withChanges, inside generatedWorkspaceRoot. The root is read as a full Directory (not the sparse workspace overlay) and each run changeset is chained on; if the select/query fails (invalid changeset, directory read error, engine error), the workspace-root generation aborts.

Source

Thrown at core/generators.go:345

		return dagql.ObjectResult[*Directory]{}, err
	}
	var root dagql.ObjectResult[*Directory]
	if err := dag.Select(ctx, gg.BoundWorkspace, &root, dagql.Selector{
		Field: "directory",
		Args:  []dagql.NamedInput{{Name: "path", Value: dagql.NewString("/")}},
	}); err != nil {
		return dagql.ObjectResult[*Directory]{}, fmt.Errorf("read workspace root: %w", err)
	}
	for _, cs := range changes {
		csID, err := cs.ID()
		if err != nil {
			return dagql.ObjectResult[*Directory]{}, fmt.Errorf("changeset ID: %w", err)
		}
		if err := dag.Select(ctx, root, &root, dagql.Selector{
			Field: "withChanges",
			Args:  []dagql.NamedInput{{Name: "changes", Value: dagql.NewID[*Changeset](csID)}},
		}); err != nil {
			return dagql.ObjectResult[*Directory]{}, fmt.Errorf("apply changes to workspace root: %w", err)
		}
	}
	return root, nil
}

// verifySkippedModule loads one skipped module from the generated workspace
// root and records the outcome on its "regenerated" span: OK, or the described
// post-generation load error. The span's status is the whole answer; the
// report words a success itself (idtui regeneratedModuleMessage).
func verifySkippedModule(ctx context.Context, generated dagql.ObjectResult[*Directory], failure ModuleLoadFailure) {
	var rerr error
	ctx, span := Tracer(ctx).Start(ctx, failure.Name,
		telemetry.Reveal(),
		trace.WithAttributes(
			attribute.Bool(telemetryattrs.GenerateRegeneratedAttr, true),
			attribute.Bool(telemetry.UIRollUpLogsAttr, true),
			attribute.Bool(telemetry.UIRollUpSpansAttr, true),
		),

View on GitHub (pinned to 82ba2681db)

Solutions

1. Inspect the wrapped cause (%w) — it names the actual withChanges failure
2. Re-run with a healthy engine cache; clear or GC corrupted engine cache state if blobs are unreadable
3. Ensure CLI and engine versions match (dagger engine upgrade / CLI upgrade in lockstep)
4. If a specific module's changeset triggers it, regenerate that module in isolation to identify the offending changes

// Verify the base directory resolves before applying changes:
var probe dagql.ObjectResult[*Directory]
if err := dag.Select(ctx, gg.BoundWorkspace, &probe, dagql.Selector{
    Field: "directory",
    Args:  []dagql.NamedInput{{Name: "path", Value: dagql.NewString("/")}},
}); err != nil {
    return fmt.Errorf("workspace root unreadable: %w", err)
}

if err := dag.Select(ctx, root, &root, dagql.Selector{Field: "withChanges", Args: ...}); err != nil {
    if errors.Is(err, context.DeadlineExceeded) {
        // retry with a larger timeout
    }
    return fmt.Errorf("apply changes to workspace root: %w", err)
}

When it happens

Trigger: generatedWorkspaceRoot iterating over run changesets when dag.Select(ctx, root, &root, {Field: "withChanges"}) returns an error — e.g. the changeset ID is invalid, the base directory failed to materialize, or the engine errored evaluating withChanges.

Common situations: Engine storage/cache corruption preventing the base directory or changeset blobs from being read; a changeset produced by a failed/aborted generator step; very large changesets failing during evaluation; version mismatch between CLI and engine causing field/argument incompatibilities.

Related errors

• encode persisted generated code: missing code directory
• attach generated code directory: unexpected result %T
• compute structural diff: %w
• read workspace root: %w
• namespace interface function id: %w

AI-assisted analysis of dagger/dagger@82ba2681db (2026-09-05). Data as JSON: /api/errors/e049a2f8e35e9152. Report an issue: GitHub.