introduce ELECTRON_NO_ASAR

docs/api/environment-variables.md

@@ -43,6 +43,10 @@ By default, a newly generated Google API key may not be allowed to make
 geocoding requests. To enable geocoding requests, visit this page:
 https://console.developers.google.com/apis/api/geolocation/overview
 
+### `ELECTRON_NO_ASAR`
+
+Disables ASAR support. Note that this variable can only be used when forking a process to disable any ASAR support in that process.
+
 ## Development Variables
 
 The following environment variables are intended primarily for development and

lib/common/asar.js

@@ -34,7 +34,7 @@
   // Separate asar package's path from full path.
   const splitPath = function (p) {
     // shortcut to disable asar.
-    if (process.noAsar) {
+    if (process.noAsar || process.env.ELECTRON_NO_ASAR) {
       return [false]
     }