trying to add fltk 1.1.9

[Genedyne]

Trying to add fltk 1.1.9 to buildroot config.
I've made several patches (most of which was to delete the patches
that came with the default fltk 1.1.7 buildroot 'package' directory -
they no longer apply).

Anyway I finally got the package to compile, but the linker complains:
----------------------
(...)../i686-linux-uclibc/bin/ld: errno@@GLIBC_PRIVATE: TLS definition
in /lib/libc/so.6 section .tbss mismatches non-TLS definition in
(...)buildroot/build_1686/staging_dir//lib/libc.so.o section .bss
(...) buildroot/build_i686/staging_dir//lib/libc.co.0: could not read
symbols: Bad value
collect2: ld returned 1 exit status
----------------------
The TLS / non-TLS issue appears to be related to building something
thread-safe (TLS = Thread Local Storage). It appears that ld thinks
libc.so.6 was build with a TLS version of errno, while libc.so.0 was
NOT. the toolchain was built with NPTL threading enabled, so
everything should be build threadsafe.

Any ideas / hints on what I should be looking at?

Thanks,
Robb.