ehlo,
The functions strdup and strncmp are used in pam_test_client,
but header file string.h was not included directly in this file.
The header file string.h was indirectly included by the header file
security/pam_client.h.
sh-4.2$ nm --undefined-only ./pam_test_client | grep -E "strdup|strncmp"
U __strdup@(a)GLIBC_2.2.5
U strncmp@(a)GLIBC_2.2.5
patch is attached.
LS