> checking for poptGetContext in -lpopt... no
> checking whether to build with POPT library... no
>
> This is because it misses a libtool dependency*:
...
> * PS. this dependency is new for popt 1.14,
>       as popt 1.13 didn't depend on libiconv.

Apparently this also works, to disable iconv usage:
CPPFLAGS += -DPOPT_fprintf=fprintf (i.e. for popt)

--anders