Paket.lock contains some dependencies multiple times.

Description

I see stuff like

    Chessie (0.6)
      FSharp.Core  - restriction: || (== net46) (&& (== netcoreapp2.0) (< netstandard1.6)) (&& (== netstandard2.0) (< netstandard1.6))
      FSharp.Core (>= 4.0.1.7-alpha) - restriction: || (&& (== net46) (>= netstandard1.6)) (== netcoreapp2.0) (== netstandard1.6) (== netstandard2.0)
      NETStandard.Library (>= 1.6) - restriction: || (&& (== net46) (>= netstandard1.6)) (== netcoreapp2.0) (== netstandard1.6) (== netstandard2.0)

In the lock file. This sounds very wrong and bad, usually we try to unify equal dependencies across dependency groups.
At least we should take a look if this has some surprising side-effects. I saw this in the past and it lead to several critical bugs back then... The only thing I'm wondering is why we don't have a lot of bug reports coming in...

Also what does Paket resolve to if a single package has two dependency groups with conflicting dependencies? Does it report an error?

Start with the duplicated dependency groups shown in Paket.lock and reproduce the resolution using the reported package constraints. Trace how Paket handles repeated or conflicting dependencies, then document the observed behavior and add regression coverage if the repository provides a suitable test location.