-To build sudo from the source distribution you need a machine running
-Unix (most flavors of BSD, SYSV, or POSIX will do), a working C
-compiler, and the ar, make and ranlib utilities.
+To build sudo from the source distribution you need a nominally
+POSIX-compliant operating system (any modern version of BSD, Linux
+or UNIX should work), a working ANSI/ISO C compiler (C89 or higher),
+and the ar, make and ranlib utilities