Cannot use yarn with flat dependency structure

[chimon2000]

Description of Problem
When attempting to use yarn with "flat":true set in the package.json, attempting to build after adding resolutions results in build errors.

In a couple of cases, regardless of the dependency I choose I still get errors building the project. I believe this is because some of FuseBox's dependencies use different versions of the same modules.

[nchanged]

Interesting, can you reproduce the issue in a repository?

[Shepless]

@chimon2000 is this still an issue for you?