Error: Unknown variable - There is no variable named "dependency"

TL;DR: Terragrunt evaluates an included remote_state block before dependency outputs exist, so a shared remotestate that references dependency.* prints Error: Unknown variable even though the run succeeds. Stop referencing dependency inside shared remotestate blocks; build the state key from locals or static values instead.

ERROR Error: Unknown variable
ERROR   on /tmp/tg-repro/_shared/remote_state.hcl line 8, in remote_state:
ERROR    8:     path = "${dependency.sub.outputs.id}-${dependency.rgs.outputs.name}.tfstate"
ERROR There is no variable named "dependency".

(The run then completes with EXIT=0; the errors are noise from partial-parse passes.)

Steps

1. Confirm the errors are the spurious kind: the run exits 0 and the real terraform output (e.g. No changes) appears after them.

Expected: plan/apply output is present and correct.

1. Find the dependency.* reference inside the included remote_state block.

Expected: something like path = "${dependency.x.outputs.y}-..." in a shared file.

1. Rewrite the key without dependency outputs: use path_relative_to_include(), a static naming convention, or a local read from a config file.

Expected: no dependency. references remain in any included remote_state block.

1. Re-run the same command.

Expected: the Unknown variable errors are gone.

When this applies

• terragrunt plan prints Error: Unknown variable / There is no variable named "dependency" pointing at a shared remote_state file, but exits 0.
• The reference is inside an included config, not the unit's own file.

When it doesn't apply

• A genuinely missing dependency "name" block in the unit: then the error is real and the fix is to add the block.
• Error: Unsupported attribute on dependency.x.outputs.y: that's a missing output or unapplied dependency, different fix (mock_outputs).

Tool versions

Terragrunt 1.x (reported on recent 1.1.x).

Why it happens

Terragrunt parses included configs in multiple passes. During an early pass triggered while resolving the unit's own dependency blocks, the included remote_state is evaluated before any dependency outputs exist, so dependency is unbound and each evaluation prints the error. Later passes succeed, which is why the exit code stays 0.

Edge cases

• If you truly need a dynamic state key per dependency, compute it in the unit's own locals (where dependency is in scope at the right stage) and pass it into the shared file via expose, rather than referencing dependency inside the shared file directly.