[Haskell-beginners] Why is cabal trying to install a particular dependency?

[Ben Gamari]

On August 28, 2014 8:18:53 AM EDT, Peter <voldermort at hotmail.com> wrote:
>Sometimes I want to know why installing package X will require package
>Y.
>After a lot of recursive manual inspection of .cabal files and
>--dry-run, I
>discover that X depends on A, which depends on B, which depends on C,
>which
>requires Y unless some flag is specified.
>
>Is there a way to ask cabal to tell me this?
>
Passing -v3 to cabal will cause it to emit all manner of useful (and less than useful) information. It's particularly handy when trying to identify which package is holding back a dependency.

Unfortunately it can be a bit tricky to quickly parse but grep can help here.

Cheers,

- Ben