Hello Sebastian, Thank for the detailed bug report. I will work with the upstream author to add the symbols file and the binNMU.
Thank you, tony On Mon, Oct 05, 2026 at 11:18:52PM +0200, Sebastien Bacher wrote: > Package: libbobcat6 > Version: 6.15.01-1 > Severity: serious > Justification: Policy 8.6.2 (ABI change without soname bump), breaks > filtermail > Control: affects -1 filtermail > > Hi, > > Between 6.11 and 6.15, bobcat removed the out-of-line special member > functions of FBB::Pattern. In 6.11 these were defined in > pattern/destructor.cc, > destroy.cc, etc.; in 6.15 the class no longer declares them, so they are > implicitly generated in each user. The library soname is still > libbobcat.so.6, > so binaries built against the older headers still reference the old symbols, > and some of those are no longer exported by libbobcat.so.6.15.01. > > In total, 37 dynamic symbols exported by 6.11.00 are gone in 6.15.01, > among them: > > FBB::Pattern::Pattern(FBB::Pattern&&) > FBB::Pattern::operator=(FBB::Pattern&&) > FBB::Pattern::operator=(FBB::Pattern const&) > FBB::Pattern::copy(FBB::Pattern const&) > FBB::Pattern::destroy() > > Impact in unstable/forky: filtermail 1.07.01-1 (built in April against an > older libbobcat-dev) is linked with BIND_NOW and does not start with > libbobcat6 6.15.01-1: > > $ filtermail --help > filtermail: symbol lookup error: filtermail: undefined symbol: > _ZN3FBB7PatternaSEOS0_ > > (_ZN3FBB7PatternaSEOS0_ = FBB::Pattern::operator=(FBB::Pattern&&)) > > I checked the other packages linking libbobcat6 in unstable (bisonc++, > flexc++, > gpg-remailer, guncat, multispeech, natlog, oxref, simrisc, ssh-cron, > stealth, > xd). Against the Debian 6.15.01-1 library they currently only need weak > references or symbols that are still exported, so filtermail is the only > binary I found failing. That is partly luck: FBB::Pattern::~Pattern() is no > longer defined in the 6.15 sources but is still exported by the Debian > build. > In Ubuntu, which builds with -flto=auto, ~Pattern() is not exported, and > flexc++, bisonc++, gpg-remailer, oxref and stealth also fail with > "undefined symbol: _ZN3FBB7PatternD1Ev". > > A no-change rebuild of filtermail (and flexc++) against libbobcat-dev > 6.15.01-1 > fixes this: the rebuilt binaries no longer reference those symbols and > run fine. > > Possible fixes: > - bump the soname (libbobcat7) for this ABI change, or > - binNMU the reverse dependencies (at least filtermail) and add > Breaks: filtermail (<< 1.07.01-1+b1) (and the others if needed) to > libbobcat6, so that old binaries cannot be combined with 6.15. > A symbols file for libbobcat6 would help catch such changes in the future. > > Thanks,
