[Haskell-cafe] already installed packages alerted as not being installed

[Kazu Yamamoto ( 山本和彦 )]

Hello,

> When I install cabal-dev and cab first and then re-install everything
> with cab instead of cabal the issue with re-installing already
> installed packages described above disappears and only an "unknown
> symbol" message related to the correctly found installed cairo package
> remains. So is there an error in package database handling somewhere
> or changed semantics in cabal | ghc-pkg | (even) pkg-config flags I
> missed?

"cab" is just a wrapper for "cabal" and "cabal-dev" for installation.
So, I have no idea about what's going on.

Please try "cab install <package> -n" to see what will happen before
typing "cab install <package>". If you find the word "reinstall", you
should not install the package because the installation operation will
break your package environment.

You can analyze package dependency with:
cab deps <package> -r
cab revdeps <package> -r
cab list -r

Adding the "-a" option displays global packages also.

I recommend to use a sandbox when you try to resolve a dependency
problem.

--Kazu