I’ve read the Simple Guide to Cabal at http://katychuang.com/cabal-guide/

It says:

create a copy of a package by running the command
cabal install
Some flags can speed up this process
--only-dependencies
-jN to build N packages in parallel
--dry-run to see what cabal plans to do (recommended)

But here’s the thing (piping a word count from —dry-run) 

$ cabal install hakyll --dry-run | wc -l     
 97
cabal install hakyll --only-dependencies  --dry-run | wc -l
      96

So it takes 20+ minutes to install a package that you just want to check out for a few minutes, while your CPU melts down in the process?  I must be missing something here…?

Thanks again for your newbie support, greatly appreciated. 

P.J.