ipsec_util.h and libipsecutil are terrible things :-)
ipsec_util.h includes libtecla.h, and libipsecutil dlopen()s openssl libraries.
libnsl needs ipsec_util.h to build, but it uses only a few common definitions from it:
I could be convenient to move those definitions into a separate header, say ipsec_def.h,
to make sources not so tightly coupled.
Updated by Dan McDonald about 7 years ago
Hmmm, according to ldd, libnsl doesn't link in libtecla or openssl:
osdev3(~)% ldd /lib/libnsl.so.1 libmp.so.2 => /lib/libmp.so.2 libmd.so.1 => /lib/libmd.so.1 libc.so.1 => /lib/libc.so.1 libm.so.2 => /lib/libm.so.2 osdev3(~)%
Does use of libnsl cause a dlopen() of libcrypto from openssl? A reproducible test case would be nice here.