disable babel cache

Summary: as per title. see explanation in code comment

Reviewed By: jknoxville

Differential Revision: D14125820

fbshipit-source-id: 9b8e31214a65a184397852544cebd7b69ea0aadb

static/transforms/index.js

@@ -99,6 +99,10 @@ function transform({filename, options, src}) {
 
 module.exports = {
   transform,
+  // Disable caching of babel transforms all together. We haven't found a good
+  // way to cache our transforms, as they rely on side effects like env vars or
+  // the existence of folders in the file system.
+  getCacheKey: () => Math.random().toString(36),
   process(src, filename, config, options) {
     return transform({
       src,