You're receiving this bug because the package in Summary has produced _FORTIFY_SOURCE related warnings indicating the presence of a sure overflow in a static buffer.
Even though this is not always an indication of a security problem it might even be. So please check this out ASAP.
By the way, _FORTIFY_SOURCE is disabled when you disable optimisation, so don't try finding out the cause using -O0.
Your friendly neighborhood tinderboxer
Created attachment 247813 [details]
Created attachment 253949 [details, diff]
Patch to sipcalc-1.1.4.ebuild to fix reported overflow (and one other warning)
This patch adds two sed statements. The first fixes a format string warning. The second adjusts the offending snprintf statements to use sizeof() to compute the length, which fixes the _FORTIFY_SOURCE warning.
Version 1.1.5 which is in the tree doesn't suffer from this issue. Thank you Kevin for your contribution.