-you are considering using the GNU C compiler you should use the gcc
-2.95.3 since all older gcc releases are known to produce broken code
-when compiling Perl. One manifestation of this brokenness is the
-lib/sdbm test dumping core; another is the op/regexp and op/pat,
-or ext/Storable tests dumping core (depending on the GCC release).
+you are considering using the GNU C compiler you should use at the
+very least the release of 2.95.3 since all older gcc releases are
+known to produce broken code when compiling Perl. One manifestation
+of this brokenness is the lib/sdbm test dumping core; another is many
+of the op/regexp and op/pat, or ext/Storable tests dumping core
+(the exact pattern of failures depending on the GCC release and
+optimization flags).
+
+Both the native cc and gcc seem to consume lots of memory when
+building Perl. toke.c is a known trouble spot when optimizing:
+256 megabytes of data section seems to be enough. Another known
+trouble spot is the mktables script which builds the Unicode support
+tables. The default setting of the process data section in Tru64
+should be one gigabyte, but some sites/setups might have lowered that.
+The configuration process of Perl checks for too low process limits,
+and lowers the optimization for the toke.c if necessary, and also
+gives advice on how to raise the process limits
+(for example: C<ulimit -d 262144>)
+
+Also, Configure might abort with
+
+ Build a threading Perl? [n]
+ Configure[2437]: Syntax error at line 1 : 'config.sh' is not expected.
+
+This indicates that Configure is being run with a broken Korn shell
+(even though you think you are using a Bourne shell by using
+"sh Configure" or "./Configure"). The Korn shell bug has been reported
+to Compaq as of February 1999 but in the meanwhile, the reason ksh is
+being used is that you have the environment variable BIN_SH set to
+'xpg4'. This causes /bin/sh to delegate its duties to /bin/posix/sh
+(a ksh). Unset the environment variable and rerun Configure.