This repo reproduces an issue observed when compiling a much larger project with spack.
To build run yarn install and npx spack.
The compiled bundle does not include the code for the memoize function which is imported in src/util.js, see the output in dist/main.js.
This in turn leads to a ReferenceError at runtime:
Uncaught ReferenceError: memoize is not defined
I suspect this is a bug in the tree shaking algorithm.