fix error in evaluating dynamic variables with newly created directory

internal/execext/exec.go

@@ -47,10 +47,10 @@ func RunCommand(ctx context.Context, opts *RunCommandOptions) error {
 
 	r, err := interp.New(
 		interp.Params("-e"),
-		interp.Dir(opts.Dir),
 		interp.Env(expand.ListEnviron(environ...)),
 		interp.OpenHandler(openHandler),
 		interp.StdIO(opts.Stdin, opts.Stdout, opts.Stderr),
+		dirOption(opts.Dir),
 	)
 	if err != nil {
 		return err
@@ -87,3 +87,24 @@ func openHandler(ctx context.Context, path string, flag int, perm os.FileMode) (
 	}
 	return interp.DefaultOpenHandler()(ctx, path, flag, perm)
 }
+
+func dirOption(path string) interp.RunnerOption {
+	return func(r *interp.Runner) error {
+		err := interp.Dir(path)(r)
+		if err == nil {
+			return nil
+		}
+
+		// If the specified directory doesn't exist, it will be created later.
+		// Therefore, even if `interp.Dir` method returns an error, the
+		// directory path should be set only when the directory cannot be found.
+		if absPath, _ := filepath.Abs(path); absPath != "" {
+			if _, err := os.Stat(absPath); os.IsNotExist(err) {
+				r.Dir = absPath
+				return nil
+			}
+		}
+
+		return err
+	}
+}

task_test.go

@@ -877,6 +877,33 @@ func TestWhenDirAttributeItCreatesMissingAndRunsInThatDir(t *testing.T) {
 	_ = os.RemoveAll(toBeCreated)
 }
 
+func TestDynamicVariablesRunOnTheNewCreatedDir(t *testing.T) {
+	const expected = "created"
+	const dir = "testdata/dir/dynamic_var_on_created_dir/"
+	const toBeCreated = dir + expected
+	const target = "default"
+	var out bytes.Buffer
+	e := &task.Executor{
+		Dir:    dir,
+		Stdout: &out,
+		Stderr: &out,
+	}
+
+	// Ensure that the directory to be created doesn't actually exist.
+	_ = os.RemoveAll(toBeCreated)
+	if _, err := os.Stat(toBeCreated); err == nil {
+		t.Errorf("Directory should not exist: %v", err)
+	}
+	assert.NoError(t, e.Setup())
+	assert.NoError(t, e.Run(context.Background(), taskfile.Call{Task: target}))
+
+	got := strings.TrimSuffix(filepath.Base(out.String()), "\n")
+	assert.Equal(t, expected, got, "Mismatch in the working directory")
+
+	// Clean-up after ourselves only if no error.
+	_ = os.RemoveAll(toBeCreated)
+}
+
 func TestDynamicVariablesShouldRunOnTheTaskDir(t *testing.T) {
 	tt := fileContentTest{
 		Dir:       "testdata/dir/dynamic_var",

testdata/dir/dynamic_var_on_created_dir/Taskfile.yml

@@ -0,0 +1,10 @@
+version: '3'
+
+tasks:
+  default:
+    dir: created
+    cmds:
+      - echo {{.TASK_DIR}}
+    vars:
+      TASK_DIR:
+        sh: echo $(pwd)