GHCi vs iconv_open

[dt71 at gmx.com]

After a recent installworld, GHCi (``ghc -i'' from lang/ghc) fails like so:

% ghci
GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... ghc: /usr/local/lib/ghc-7.6.3/base-4.6.0.1/HSbase-4.6.0.1.o: unknown symbol `iconv_open'
ghc: unable to load package `base'

Running portupgrade to rebuild all (most) ports didn't help. Where's the issue / Do what?