I upgraded to 4.14 and builded stunnel with all three threading models:
1) ucontext gave the same problem as the above mentioned 4.11 ucontext version
2) pthread gave me a strange error during the "./config" phase:
checking pthread.h usability... no
checking pthread.h presence... yes
configure: WARNING: pthread.h: present but cannot be compiled
configure: WARNING: pthread.h: check for missing prerequisite headers?
configure: WARNING: pthread.h: see the Autoconf documentation
configure: WARNING: pthread.h: section "Present But Cannot Be Compiled"
configure: WARNING: pthread.h: proceeding with the preprocessor's result
configure: WARNING: pthread.h: in the future, the compiler will take
precedence
configure: WARNING: ## ------------------------------
---- ##
configure: WARNING: ## Report this to the stunnel lists. ##
configure: WARNING: ## ---------------------------------- ##
checking for pthread.h... yes
After this, i couldn't build the software in the "make" phase. I'm
sorry i forgot to capture that error, but it came from the pthread.h
header file. I'll capture the entire error next week if you're
interested.
For the time being i'm also looking for another build-machine, because
i'm not sure this problem can be caused by an old version of GCC (2.9,
shame).
3) the fork option builded nicely, no warnings whatsoever, but has the
same behaviour as the ucontext build, crashes with both syslog and
engine=chil enabled.
I haven't had the possibility to use truss on the binary's, hopelfully i'll try that next week.