Bug#696259: Discourage (preferably forbid) underlinked public shared libraries
Hereinafter "libraries" means "public shared libraries" per Policy §8 and only
I couldn't find in the Policy anything about underlinked libraries while I
believe that having them is wrong and should be considered a bug.
I mean libraries that are not directly linked against all libraries whose
symbols are used. In the worst case this manifests as "undefined reference"
lines in the ldd -r output and means that you must satisfy these references by
linking additional libraries to the binaries that use the underlinked library
(by linking against it or dlopening it). If you don't do this, sometimes you
may not notice the problem until you invoke a specific code path that uses
these references. Formally this also means that packages using the underlinked
library may have RC bugs that can't be fixed, only worked around by linking
additional libraries (cf. #694846 caused by #677721).
In some cases a library doesn't have undefined symbols because of indirect
dependencies but that's just a hidden bug and it can appear at any time when
indirect deps change. In this case ldd won't show undefined references but
automatic detection of the problem should still be possible.
Also, if a library is underlinked we cannot use the dpkg dependencies to
document the library dependencies. Also, underlinking of a library causes
overlinking for binaries that use it and that is a problem by itself.
See also http://wiki.mandriva.com/en/Underlinking
So, I propose adding something like "Shared libraries should be linked against
all libraries they use directly" to §8.1.
-- System Information:
Debian Release: 7.0
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.7.0-wrar-1+ (SMP w/4 CPU cores; PREEMPT)
Locale: LANG=ru_RU.UTF-8, LC_CTYPE=ru_RU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash