Maybe we can use a root tsconfig.json and the one tsconfig.build.json per package.
Although I can’t remember right now if I already tried that and it gave me problems…
I’ll try it this way in core and see what happens.
By the way, I’ve just installed a lerna package in devDependencies and it works fine when doing npm i at the root 
Yes, I think my problem is that the @frontity/core main file doesn’t exist and therefore the error.
I noticed that if we keep the tsconfig.json on the root, we should be mindful to set noEmit to false in the local tsconfig.build.json file.
Sounds fine.
Yes, we could do that, and change the prepare script to execute that.
Ok, my problem was definitely that the main file didn’t exist, so it couldn’t be required. Not a lerna problem.