Using dynamic import with npm compatibility gives intermittent error "__DENO_NODE_GLOBAL_THIS_167935

This is pretty hard to google because the number at the end of the error changes everytime it happens, but basically: is this a known issue? I'll run some code (in a worker, using dynamic import pointing to npm:npm: or a CDN and get ReferenceError: __DENO_NODE_GLOBAL_…ReferenceError: __DENO_NODE_GLOBAL_… on the first and sometimes second run, but after that it'll work.