Hi,
I am building a recent stunnel version for Solaris via opencsw.org and with 4.44 it seems as if --with-ssl is used to AC_SUBST([SSLDIR]), yet tools/Makefile uses lowercase $(ssldir). Lead to an empty expansion and failed calls to openssl in my case.
$ grep -i ssldir Makefile tools/Makefile Makefile:SSLDIR = /opt/csw tools/Makefile:SSLDIR = /opt/csw tools/Makefile:openssl = $(ssldir)/bin/openssl
Sebastian