/usr/bin/ld: /usr/local/lib/libssl.a(s23_srvr.o): relocation R_X86_64_32
against `.rodata' can not be used when making a shared object; recompile
with -fPIC
/usr/local/lib/libssl.a: could not read symbols: Bad value
collect2: ld returned 1 exit status
make: *** [libunbound.la] Error 1
You have only libssl.a compiled (it seems), and no libssl.so, and the
build of libunbound.so fails, but you can still build the static
library fine. You could also recompile ssl to fix this bug, but you
have to enable shared library support in openssl then.