What causes "load workspace arg %q: %w" in dagger/dagger?

Run the command from within a valid dagger module directory (where dagger.json exists).

load workspace arg %q: %w

Error message

load workspace arg %q: %w

What it means

DynamicInputsForCall automatically injects the current workspace (module directory) into arguments typed for it when not supplied. If fn.loadWorkspaceArg fails, the error is wrapped as "load workspace arg %q" naming the argument that would have received the workspace.

Source

Thrown at core/modfunc.go:740

					return nil
				}

				ctxArgVals[i] = &argInput{
					argName: arg.Name,
					val:     ctxVal,
				}

				return nil
			})
		}

		// Process workspace arguments - automatically inject workspace when not set
		workspaceArgVals := make([]*argInput, len(workspaceArgs))
		for i, arg := range workspaceArgs {
			eg.Go(func() error {
				wsVal, err := fn.loadWorkspaceArg(ctx, srv)
				if err != nil {
					return fmt.Errorf("load workspace arg %q: %w", arg.Name, err)
				}

				workspaceArgVals[i] = &argInput{
					argName: arg.Name,
					val:     wsVal,
				}

				return nil
			})
		}

		// Process user-defined user defaults for objects (and lists of objects)
		type userDefaultArgInput struct {
			argName string
			val     dagql.Input
		}
		userDefaultVals := make([]*userDefaultArgInput, len(userDefaults))
		for i, userDefault := range userDefaults {

View on GitHub (pinned to 82ba2681db)

Solutions

Run the command from within a valid dagger module directory (where dagger.json exists).
Pass the directory argument explicitly instead of relying on workspace injection.
Verify the module source directory loads correctly (git status, file permissions).
Check the wrapped inner error for the underlying workspace load failure.

Example fix

# before (run outside module)
cd /somewhere && dagger call build
# after
cd /path/to/my-module && dagger call build

Defensive patterns

Strategy: validation

Validate before calling

# Ensure the command runs inside a valid dagger module (dagger.json present)
if [ ! -f dagger.json ]; then echo "not in a dagger module"; exit 1; fi

Try / catch

_, err := fn.Call(ctx, args)
if err != nil && strings.Contains(err.Error(), "load workspace arg") {
	// supply the workspace directory explicitly
	args["workspace"] = dag.Host().Directory(".")
	_, err = fn.Call(ctx, args)
}

Prevention

Always run dagger call from a directory containing dagger.json.
Pass workspace-typed arguments explicitly in scripts that may run outside the module root.
Verify git worktrees/checkouts in CI include the module source.
Check the inner error for the actual workspace load failure.

When it happens

Trigger: Calling a function with a parameter qualifying for automatic workspace injection, while resolving the workspace itself fails — e.g. the module has no valid source directory in this context.

Common situations: Running dagger call outside a valid module context; the module source directory failed to load; git worktree/checkout issues in CI making the workspace unresolvable.

Related errors

AI-assisted analysis of dagger/dagger@82ba2681db (2026-09-05). Data as JSON: /api/errors/187759d5ef5fdd8a. Report an issue: GitHub.