I’m setting up a new GitHub repo to demonstrate using Terraform with Azure Pipelines via the CLI and I hit a weird error right at the start. I was using Jason Johnson’s Azure Pipelines Terraform Tasks extension like this:

- task: TerraformCLI@2
  inputs:
    command: init
    workingDirectory: "$(System.DefaultWorkingDirectory)/v2"
    backendType: selfConfigured
    commandOptions: -no-color -input=false
    allowTelemetryCollection: false

and it kept failing with the error:

/opt/hostedtoolcache/terraform/1.6.4/x64/terraform version
Terraform v1.6.4
on linux_amd64
+ provider registry.terraform.io/hashicorp/azurerm v2.99.0
+ provider registry.terraform.io/hashicorp/random v3.5.1
/opt/hostedtoolcache/terraform/1.6.4/x64/terraform init --input=false --no-color
Usage: terraform [global options] init [options]
...
Terraform command 'init' failed with exit code '1'.

I tried all sorts of things. It looked identical to other pipelines I had working (and ones I’d seen online). Was there a weird invisible character being passed on the command line? Out of desperation I copied the commandOptions line from another pipeline (which looked identical except that the arguments were in a different order).

But when I looked at the diff, not only were the arguments different, I realised that the dashes were different too! Terraform CLI arguments use a single dash, not a double dash. So the correct line is

commandOptions: -no-color -input=false

In hindsight, I realised that this is the first pipeline I’ve written on GitHub using the Terraform CLI (e.g. not in a work context) and so I did it manually, rather than copy/pasting from an existing (working) pipeline. A pity Terraform doesn’t support double dashes, but there you go.