When installing the net-libs/libnice-0.0.13 package on my Gentoo system, I received the following notification:

 * QA Notice: Package has poor programming practices which may compile
 *            fine but exhibit random runtime failures.
 * test-parse.c:711: warning: implicit declaration of function ‘stun_hash_creds’

 * Please do not file a Gentoo bug and instead report the above QA
 * issues directly to the upstream developers of this software.
 * Homepage: http://nice.freedesktop.org/wiki/
 * ERROR: net-libs/libnice-0.0.13 failed:
 *   install aborted due to poor programming practices shown above



Looking through the build output, here is the warning in context:


Making check in tests
make[2]: Entering directory `/var/tmp/portage/net-libs/libnice-0.0.13/work/libnice-0.0.13/stun/tests'
make  test-parse test-format test-bind test-conncheck test-hmac \
          check-bind.sh
make[3]: Entering directory `/var/tmp/portage/net-libs/libnice-0.0.13/work/libnice-0.0.13/stun/tests'
i686-pc-linux-gnu-gcc -DHAVE_CONFIG_H -I. -I../..  -I../..  -std=gnu99 -O2 -march=i686 -pipe -MT test-parse.o -MD -MP -MF .deps/test-parse.Tpo -c -o test-parse.o test-
parse.c
test-parse.c: In function ‘test_hash_creds’:
test-parse.c:711: warning: implicit declaration of function ‘stun_hash_creds’
mv -f .deps/test-parse.Tpo .deps/test-parse.Po
/bin/sh ../../libtool --tag=CC   --mode=link i686-pc-linux-gnu-gcc -std=gnu99 -O2 -march=i686 -pipe  -Wl,-O1 -Wl,--as-needed -o test-parse test-parse.o ../../stun/libstun.la