I'm currently packaging Jenkins for Ubuntu; this application has native authentication integration through the use of PAM. This was working fine i.e. the java native interface dispatcher was able to find libpam.so in /lib and all was happy.
I've just updated my test system and native authentication no longer works; the JNI dispatcher can't find the library. I have done a bit of digging and it looks like libpam.so.* is installed to /lib/i386-linux-gnu instead of /lib (as on Maverick and possibly earlier Natty releases?). This directory is not on the java.library.path by default which I suspect may be the issue (see below for default java library path):
So I'm not sure whether this is a bug in pam or openjdk but I guess it could be either.
DistroRelease: Ubuntu 11.04
Package: libpam0g 1.1.2-2ubuntu4
ProcVersionSignature: Ubuntu 2.6.38-7.35-generic-pae 2.6.38
Uname: Linux 2.6.38-7-generic-pae i686
Date: Fri Mar 18 14:54:45 2011
InstallationMedia: Ubuntu-Server 11.04 "Natty Narwhal" - Alpha i386 (20110301.4)
PATH=(custom, no user)
UpgradeStatus: No upgrade log present (probably fresh install)