Set parent process env in steps running on host VM (#39)

engine/engine.go

@@ -83,6 +83,15 @@ func (e *Engine) Run(ctx context.Context, step *spec.Step, output io.Writer) (*r
 	e.mu.Unlock()
 
 	envs := make(map[string]string)
+	if step.Image == "" {
+		// Set parent process envs in case step is executed directly on the VM.
+		// This sets the PATH environment variable (in case it is set on parent process) on sub-process executing the step.
+		for _, e := range os.Environ() {
+			if i := strings.Index(e, "="); i >= 0 {
+				envs[e[:i]] = e[i+1:]
+			}
+		}
+	}
 	for k, v := range cfg.Envs {
 		envs[k] = v
 	}