packages like pg-then will require('pg') even though they don't declare it as a dependency. This works with npm since pg-then ends up being installed in the same node_modules folder as pg but when they are symlinked from a global store this doesn't work. And babel-runtime does require('babel-runtime'). haha

These packages should declare these dependencies in "peerDependencies" but they don't because with npm they can get away without it.

And BTW the hackery I mentioned in #1 won't be necessary if pnpm support "peerDependencies" and if packages use it correctly