[Haskell-beginners] Cabal: Upgrading to the latest version of library

[Hugo Ferreira]

Hello,

Recently I had to update and install a newer version of a library.
I executed the "cabal update", which downloads the latest package list.
I had assumed that this command would also detect, build and install
those libraries that have been upgraded. However this does not seem to
be the case. I had to manually build the library and then use GHC's
package manager do unregister the old version.

My question is: how does one check for and upgrade the cabal libraries
automatically?

TIA,
Hugo F.