Merge pull request #18946 from atom/aw/electron-version-in-build-env

Set Electron version within the build process environment

script/build

@@ -57,6 +57,8 @@ process.on('unhandledRejection', function (e) {
 })
 
 const CONFIG = require('./config')
+process.env.ELECTRON_VERSION = CONFIG.appMetadata.electronVersion
+
 let binariesPromise = Promise.resolve()
 
 if (!argv.existingBinaries) {