Terraform: v0.12 'Error: Ambiguous attribute key' thrown for simple, non-literal key

[mavin]

Terraform Version

Terraform v0.12.0

Terraform Configuration Files

terraform {
  required_version = ">= 0.12"
}

variable "name_test" {
  default = "hello"
}

locals {
  hash = {
    (var.name_test) = "world",
  }
}

Debug Output

https://gist.github.com/mavin/4e796c4d43b233ce75f2a8cfc9557141

Expected Behavior

The given config should be valid, according to the docs; if it isn't then there should be a more helpful error message.

Actual Behavior

An error is thrown that recommends changes that are already present in the config.

$ terraform validate

Error: Ambiguous attribute key

  on vars.tf line 11, in locals:
  11:     (var.name_test) = "world",

If this expression is intended to be a reference, wrap it in parentheses. If
it's instead intended as a literal name containing periods, wrap it in quotes
to create a string literal.

Steps to Reproduce

1. terraform init
2. terraform validate

Additional Context

All this happens with a fresh environment and a new config.

[apparentlymart]

Thanks for reporting this, @mavin!

This is indeed a bug, probably in the underlying HCL library. :confounded: We'll investigate it.

In the mean time, you may be able to get this to work by using the interpolation syntax as an alternative way to disambiguate it:

    "${var.name_test}" = "world",

[mavin]

:taco:

[RatkoD]

Is this still a bug or we need to refactor our code to comply with the new syntax? I'm using v0.11.13.

[ksharma26]

I am trying to upgrade our (huge) repo from V0.11.14 to 0.12.14. It does not look viable to manually change to interpolation syntax everywhere. Is there a better way to get it working until we fix this bug?

[ktham]

@apparentlymart Given that 0.13 is coming soon, does it make sense to assume that this bug won't be fixed in 0.12?

[alisdair]

This bug was actually fixed in 0.12.10, as part of this PR updating the HCL version. It continues to be fixed in 0.13.

$ cat main.tf
terraform {
  required_version = ">= 0.12"
}

variable "name_test" {
  default = "hello"
}

locals {
  hash = {
    (var.name_test) = "world",
  }
}
$ terraform-0.12.9 validate

Error: Ambiguous attribute key

  on main.tf line 11, in locals:
  11:     (var.name_test) = "world",

If this expression is intended to be a reference, wrap it in parentheses. If
it's instead intended as a literal name containing periods, wrap it in quotes
to create a string literal.

$ terraform-0.12.10 validate
Success! The configuration is valid.

$ terraform-0.12.28 validate
Success! The configuration is valid.

$ terraform-0.13.0-beta2 validate
Success! The configuration is valid.

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