IRIX

From PortaWiki

Ancient IRIX (Earlier than 6.5)

• IRIX 5.3 expects different type of argument to signal(). On IRIX 5.3 signal() is defined as follows:

C++:
 void (*signal (int sig, void (*func)(...)))(...);

• If you happen to use a variable _res in your code (as OpenSSH does/did in its getrrsetbyname implementation) then name lookups will break in interesting and unusual ways.