Undefined PLT symbol "openpam ttyconv"
Undefined PLT symbol "openpam_ttyconv" (symnum = 47)
A similar error in a chroot environment was:
Undefined symbol "_openpam_debug" referenced from COPY relocation in su
This turned out to be due to the fact that there was a libpam.so in /usr/pkg/lib, and I had placed that directory in /etc/ld.so.conf to work around other issues. My solution now has the following in /etc/ld.so.conf:
libm.so.0 machdep.fpu_present 1:libm387.so.0,libm.so.0 /lib /usr/lib /usr/X11R6/lib /usr/pkg/lib