Task variable level overrides no longer work in recent releases

[blakewatters]

Since upgrading task to latest v3.37.x releases I am seeing variable overrides for included tasks functioning as no-ops. For example, given this task include:

includes:
  staging:
    taskfile: ./taskfiles/instance.yml
    vars:
      OSIRIS_ENV: staging
      GOOGLE_CLOUD_PROJECT: whatever-staging
      BASE_URL: https://api.staging.whatever.com

  staging:bastion:
    vars:
      BASTION_INSTANCE_NAME: whatever-staging-bastion
      GOOGLE_CLOUD_PROJECT: whatever-staging
    taskfile: ./taskfiles/bastion.yml

The OSIRIS_ENV and GOOGLE_CLOUD_PROJECT remain at their default values rather than the explicitly overridden values.

• Task version: 3.37.2
• Operating system: macOS
• Experiments enabled: No

[trulede]

This is relating to import/included tasks. Where are the default values defined? Variables specified at the inclusion have a fairly low priority: https://taskfile.dev/usage/#variables

My own experiment show that this behavior is not working as expected. Global variables take precedence over variables defined at inclusion.

Taskfile

version: "3"
 
# should only be used if var not declared _anywhere_ else (BUG)
vars: 
  FOO: "FUBAR" 
 
includes:
  a:    
    taskfile: ./a/Taskfile.yml
    vars:
      FOO: "BAR"
  b:  
    taskfile: ./a/Taskfile.yml
    vars:
      FOO: "RAB"
      
tasks:
  one:
    cmds:
      - task a:two 
      - task b:two

a/Taskfile

version: "3"

# overrides variables defined on the inclusion of this Taskfile (OK)
#vars:
# FOO: "FOO"  

tasks:
  two:
    # overrides variables defined on the inclusion of this Taskfile (OK)
    #    vars:
    #      FOO: "BAR"
    cmds:
      - echo {{.FOO}}

$ ~/go/bin/task one task: [one] task a:two task: [a:two] echo FUBAR FUBAR task: [one] task b:two task: [b:two] echo FUBAR FUBAR

I don't think this is covered by the tests (global vars or environment vars). Seems like a bug. But is it the problem you observe?

[blakewatters]

Yes @trulede, you are correct. These are top-level variables that previously I was able to override at inclusion time. Now the global variables are taking precedence over the variables set at inclusion time.

This is definitely a bug/regression that has been introduced in the last several versions. Task is not honoring the precedence contract described in https://taskfile.dev/usage/#variables

[dnlopes]

I'm using this tool for the first time now, so I cannot comment on how the behavior was before.

But I think I'm experiencing the same behavior. I have 2 taskfiles (let's call them parent and child). I have some global vars defined at the child, that work as defaults (or at least, that is my goal). At inclusion time, I was expecting to be able to override these defaults from the parent. However, it seems that if I define a global variable on the child I can no longer do that. The documentation states the following:

1. Variables declared in the task definition
2. Variables given while calling a task from another (See Calling another task above)
3. Variables of the included Taskfile (when the task is included)
4. Variables of the inclusion of the Taskfile (when the task is included)
5. Global variables (those declared in the vars: option in the Taskfile)
6. Environment variables

which is consistent with the behavior I'm getting (unfortunately 😅). I'm trying to use point 4, but because point 3 (i.e., the global vars on the child), my override gets undone.

In any case, UX wise, I think it would make more sense for variables overriden at inclusion to have higher priority than the ones defined as global variables.

[pbitty]

@blakewatters I believe there is a work-around via the default function. For anything that is to be overridden, you can use:

{{ .var_name | default "default-value" }}

This worked for me:

# Taskfile.yml
version: '3'

includes:
  child-with-var: 
    taskfile: ./Taskfile.child.yml
    vars:
      VAR: value-from-parent
  child-without-var:
    taskfile: ./Taskfile.child.yml
  

tasks:
  default:
    cmds:
      - task: child-with-var
      - task: child-without-var

# Taskfile.child.yaml
version: '3'

vars:
  VAR: '{{ .VAR | default "value-from-child" }}' # This can get overridden.

tasks:
  default: echo {{.VAR}}

Output:

task: [child-with-var:default] echo VAR is value-from-parent
VAR is value-from-parent
task: [child-without-var:default] echo VAR is value-from-child
VAR is value-from-child

Would this resolve your use-case?

[pbitty]

I do see this tip here:

Vars declared in the included Taskfile have preference over the variables in the including Taskfile! If you want a variable in an included Taskfile to be overridable, use the default function: MY_VAR: '{{.MY_VAR | default "my-default-value"}}'.

(source)

This does sound like intended behaviour and not a bug. What is good about this approach is that it allows the included file to control which vars can be overridden from the outside and which ones cannot.

[vmaerten]

Hey @blakewatters,

@pbitty is right. Default is the way to go. You can find a previous issue here, where we discussed the behavior.