Regression in v3.49.0: Global sh: variables resolve to empty string in included Taskfiles #2720

Description

After upgrading from Task v3.48.0 to v3.49.0, global variables defined with sh: no longer resolve correctly when a Taskfile has includes:. The sh: variable resolves to an empty string, causing downstream variables that reference it via templating to produce incorrect values.

This regression was introduced by #2632 (commit 2cdd7d3), which shipped in v3.49.0.

Root Cause

The added line in compiler.go (line 118):

c.TaskfileVars = templater.ReplaceVars(c.TaskfileVars, &templater.Cache{Vars: result})

This mutates c.TaskfileVars after sh: dynamic variables have already been resolved by rangeFunc (lines 112-116), destroying their cached results.

Step-by-step breakdown:

1. Lines 112-116 (rangeFunc): Iterates c.TaskfileVars. For sh: vars like DYNAMIC_VAR, it calls HandleDynamicVar() which executes the shell command and stores the resolved value in the result map. At this point, result["DYNAMIC_VAR"] = "hello" ✅

2. Line 118 (the bug): ReplaceVars re-processes the original, unmodified c.TaskfileVars. In ReplaceVarWithExtra (templater.go):

   • If Ref != "" → resolves the ref (the intended fix for Reference via ref: or via {{}} Templating of included vars (global, not task) in(to) a Taskfile vars section (global, not task) doesn't work. #2405) ✅
   • If Ref == "" (like sh: vars) → calls ReplaceWithExtra on the Sh field, which only does template substitution, not shell execution. Returns a new Var{Sh: "echo hello", Value: nil} — the resolved value is lost ❌

3. Any subsequent reference to DYNAMIC_VAR sees Value: nil → resolves to empty string.

Suggested Fix

The ReplaceVars call should only process variables that actually have Ref values set, leaving already-resolved sh: variables untouched:

for k, v := range c.TaskfileVars.All() {
    if v.Ref != "" {
        resolved := templater.ResolveRef(v.Ref, &templater.Cache{Vars: result})
        c.TaskfileVars.Set(k, ast.Var{Value: resolved})
    }
}

Minimal Reproducer

Taskfile.yml:

version: "3"

includes:
  other:
    taskfile: ./Other.yml
    internal: true

vars:
  DYNAMIC_VAR:
    sh: echo "hello"
  DERIVED_VAR: "{{.DYNAMIC_VAR}} world"

tasks:
  default:
    cmds:
      - 'echo "DYNAMIC_VAR={{.DYNAMIC_VAR}}"'
      - 'echo "DERIVED_VAR={{.DERIVED_VAR}}"'
    silent: true

Other.yml:

version: "3"

tasks:
  noop:
    cmds:
      - "true"

v3.48.0: DYNAMIC_VAR=hello, DERIVED_VAR=hello world
v3.49.0: DYNAMIC_VAR=, DERIVED_VAR= world

Environment

• Task version: v3.49.0 (works on v3.48.0)
• OS: Ubuntu 24.04 (linux/arm64, GitHub Actions runner)
• Installed via: go-task/[email protected] (no version pin, so it picked up v3.49.0 automatically)