"no expansion has been registered for module" panic in v1.12.0-beta1

Fix first: upgrade to v1.12.0-rc1 or the final v1.12.0. This was a regression in the v1.12.0 beta line; it was reverted and the fix is included in v1.12.0-rc1 and later.

no expansion has been registered for module (panic)

1. Upgrade OpenTofu to v1.12.0-rc1 or newer.
2. Re-run. Expected: no panic.

When to use: the 'no expansion has been registered for module' panic on v1.12.0-beta1.

When not to use: other OpenTofu panics (different causes).

Compatibility: OpenTofu v1.12.0-beta1 (broken), v1.12.0-rc1+ (fixed). Reported in opentofu/opentofu#4019.

Variants:

• "opentofu no expansion has been registered for module"
• "opentofu 1.12 beta panic"
• "opentofu module expansion panic"

Root cause: a beta-line regression, reverted upstream.

Edge cases: do not stay on the affected beta; there is no workaround worth using when the fixed release exists.

In gh:opentofu/opentofu#4019, the issue was: ### Community note

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OpenTofu Version

OpenTofu v1.12.0-beta1
on darwin_arm64
+ provider registry.opentofu.org/hashicorp/archive v2.7.1
+ provider registry.opentofu.org/hashicorp/aws v6.40.0
+ provider registry.opentofu.org/hashicorp/awscc v1.78.0
+ provider registry.opentofu.org/hashicorp/local v2.8.0
+ provider registry.opentofu.org/hashicorp/null v3.2.4. The verified answer: This was a regression in the v1.12.0 beta line. It was reverted and the fix is included in v1.12.0-rc1 and later. Upgrade to v1.12.0-rc1 or the final v1.12.0; do not stay on the affected beta.. Issue URL: https://github.com/opentofu/opentofu/issues/4019