apt-build problems on amd64

[Michelasso <qzerty@gmail.com>]

Hello everybody,
I was thinking to use apt-build to build the few packages that aren't
yet available in kde 3.4.2 for amd64 (or in general for packages that
aren't yet available at all for amd64), but I am having some problems.

For example apt-build install kompose seems to build the package, but
then it stops immediately before installing it with a segfault:

[...]
The following NEW packages will be installed:
  kompose
0 upgraded, 1 newly installed, 0 to remove and 5 not upgraded.
Need to get 0B/85.5kB of archives.
After unpacking 283kB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  kompose
E: There are problems and -y was used without --force-yes
Segmentation fault

with this error message being cryptic since I cannot find any
reference to the --force-yes option in the man page for apt-build.
However the .deb package for kompose is effectively built in
/var/cache/apt-build/repository and I can install it "by hand" with
dpkg.

As another example instead filelight doesn't build at all:

checking for C compiler default output... configure: error: C compiler
cannot create executables
See `config.log' for more details.
make: *** [build] Error 77
[...]
Error while building filelight!
Sorry, no package to install.
Segmentation fault


So I am starting to ask if:
a) apt-build isn't yet mature to use  for amd64
b) the problems are related to the sources, configure and makefile of
some packages not ready for amd64.

Thanks to anybody who will help me to clarify these points.