Description

Requires does not check if a variable is set, it only checks is a variable is "present". As a result, variables which are set to "null/nil" will pass the required check.

Version

3.43.2

Operating system

Linux (WSL)

Experiments Enabled

No response

Example Taskfile

version: '3'
tasks:
  default:
    vars:
      A: null
      B: '{{.B}}'
    env:
      A: '{{.A}}'
      B: '{{.B}}'
      C: '{{.C}}'
    cmds:
      - echo "$A"
      - echo "$B"
      - echo "$C"
    requires:
      #vars: [A, B, C]
      vars: [A, B]

Example output:

$ task
task: [default] echo "$A"

task: [default] echo "$B"

task: [default] echo "$C"

Obviously, none of the variables are set. Swap the comment line on the requires constraint to observe the behavior change.

The related code is here:

... where it is observed that the content of variables is not checked. I have read though the PR for this feature and did not notice any conversation about this scenario. I think the documentation explains the expectation correctly:

List of variable or environment variable names that must be set if this task is to execute and run[period missing]

I appreciate that setting a variable to nil can be considered as being set ... but with how templating works in Task, I think set means set to something other than . For example here there is no difference when A is not set, or set to nil ... the default condition will be taken:

A: '{{.A | default "A"}}'