Unable to restart a job from UI in 1.6.3

[meowtini]

Nomad version

1.6.3

Operating system and Environment details

Ubuntu 22.04.3

Issue

If a job with variables is stopped from the UI, it cannot be started again.

Reproduction steps

1. Create a job that has variables without default values.
2. Start the job providing values of the variables.
3. Stop the job from the UI.
4. Start the job from the UI again.

Expected Result

The job is started.

Actual Result

The job is not started with an error message in the "Overview" tab saying the following (the variable names were redacted):

Could Not Start Job

Failed to parse job: <nil>: Unset variable "<redacted>"; A used variable must be set or have a default value; see https://www.nomadproject.io/docs/job-specification/hcl2/variables for details. <nil>: Unset variable "<redacted>"; A used variable must be set or have a default value; see https://www.nomadproject.io/docs/job-specification/hcl2/variables for details. <nil>: Unset variable "<redacted>"; A used variable must be set or have a default value; see https://www.nomadproject.io/docs/job-specification/hcl2/variables for details. <nil>: Unset variable "<redacted>"; A used variable must be set or have a default value; see https://www.nomadproject.io/docs/job-specification/hcl2/variables for details.

However, the actual values of the variables can be seen in the "HCL Variable Values" section on the "Definition" tab. The job definition on the same tab is also correct.

Everything is fine in 1.6.1, so it seems to be introduced in later versions.
It seems to be related to #18536

[jrasell]

Hi @meowtini and thanks for raising this issue. I have been able to reproduce this using main with the minimal job specification shown below. I'll pass this onto our UI engineer who will be better placed to take a look and get this added to our roadmap.

variable "count" {}

job "example" {
  group "cache" {
    count = var.count
    task "redis" {
      driver = "docker"
      config {
        image = "redis:7"
      }
    }
  }
}