Some (trivial) problem faced with stackage lts 8 and solution

I am a new Haskell user and only trying to cope with the learning curve. When I was using haskell-vim-now with lts-8-*, is showed some dependency package error. Now as I am just a beginner and don't have much time/expertise to diagnose, I changed the resolver from 8-* to 7.19 (through numerous trial-and-error) inside .stack/global-project/stack.yaml and everything was solved.

as I typed ,ht under a function to see it's type, ghc-mod was not able to infer the type. But when I added a module Name where, It worked. I guess that's how ghc-mod works and nothing to do with the plug-in or vim. But if something written in project README doesn't work accordingly, noob like me tend to think there's something wrong with the installation process or the tool.

I hope these information will be helpful for people like me who are just trying to learn Haskell.

Thanks and regards.

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Related issues: #233, #231