-Q8B- Why does the link step says that some of the functions Tcl, needs are missing when I am trying to build it?

From: -VIII- Questions on building Tcl and friends on your system

A8B. Did you run the "config" program first, by doing a "csh ./config" or
equivalent?  Without doing this, things such as strtoul or strerror
are sometimes mentioned as missing.

Tcl includes equivalents for at least the following functions and include files
which may not be found on some systems:

dirent.h       limits.h	      stdlib.h	     string.h

opendir.c      strerror.c     strstr.c	     strtol.c	    strtoul.c

strtod.c