Don't reinstall cabal-install from source in bootstrap-haskell

[hasufell]

We already have the latest version available quite reliably.

[hasufell]

@glguy

[glguy]

Thanks for the quick response on this one. This will make a much quicker install experience for now while the cabal-install binaries are up to date.

[TomMD]

Thank you @hasufell.

I'd like to note this isn't just a speed issue but also a reliability. My first attempt to run the bootstrap happened to be from my dev directory, which has many .cabal files in immediate sub directories. As a result, the new-install constraints could not be resolved and the bootstrap failed.

[hasufell]

I'd like to note this isn't just a speed issue but also a reliability. My first attempt to run the bootstrap happened to be from my dev directory, which has many .cabal files in immediate sub directories. As a result, the new-install constraints could not be resolved and the bootstrap failed.

Yeah, this is a bug, but can be easily solved by switching to a tmp directory first before doing that new-install call.