(Apologies, as I write this I only have a couple of minutes so I'm including a very non-minimal reproduction of a problem. If it turns out to be hard to reproduce, next week I can work on a minimal reproduction. Please ask, or even just close this issue if the non-minimal repro is too much of a problem! But I thought it useful to have the issue in to at least help anyone else affected.)
The following repo uses rollup-plugin-commonjs 7.0.0, and works:
https://github.com/OasisDigital/angular-aot-es2015-rollup/tree/rollup-plugin-commonjs-179
npm install; ./aot-build.sh
But with rollup-plugin-commonjs is changed to 8.0.0, it fails with the following:
node_modules/core-js/modules/_shared-key.js (7:4)
5:
6: var shared = require$$0('keys')
7: , ;
^
8: var _sharedKey = function(key){
9: return shared[key] || (shared[key] = uid(key));
I think either Buble or Uglify is objecting to the syntax, and perhaps should instead accept it - but this syntax only appears with 8.0.0, and I saw there's recently been a change to the code handling rewriting of requires.
c8c2548
... so there is some chance that @Rich-Harris will simply see my snippet above and know what caused it.