recode/gettext/libiconv problems

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

Building converters/recode fails for me (built-in iconv, pkgsrc gettext):

===> Creating toolchain wrappers for recode-3.6nb4
ERROR: libiconv>=1.9.1 is not installed; can't buildlink files.
*** Error code 1

Stop.

I'm not familiar with buildlink3/builtin to figure out what the actual problem 
is. libiconv's builtin.mk correctly detects:

$ bmake -f builtin.mk -V IS_BUILTIN.iconv  
yes