vsnprintf() is missing. zlib v1.2.1 wants it. (+)

When running configure for zlib v1.2.1 one gets this kind of report:
Checking for gcc…
gcc: not found
Building static library libz.a version 1.2.1 with cc.
Checking for unistd.h… Yes.
Checking whether to use vs[n]printf() or s[n]printf()… using vs[n]printf()
Checking for vsnprintf() in stdio.h… No.
WARNING: vsnprintf() not found, falling back to vsprintf(). zlib
can build but will be open to possible buffer-overflow security
vulnerabilities.
Checking for return value of vsprintf()… Yes.
Checking for errno.h… Yes.
Checking for mmap support… Yes.

Is there a way to port vsnprintf() to make zlib happy?
(see here too…)

Well here is the code to the vsnprintf function, maybe this will help you port it to qnx ?

iglu.org.il/lxr/source/lib/vsprintf.c#L233

Hope that is of some help to you.

Thank you.
I’ll try my best.