open("...|"). All these mean that Perl is trying to run some
external program.
+=item Timing problems
+
+Several tests in the test suite check timing functions, such as sleep(),
+and see if they return in a reasonable amount of time. If your system is
+quite busy and doesn't return quickly enough, these tests might fail.
+If possible, try running the tests again with the system under a
+lighter load.
+
=item Out of memory
On some systems, particularly those with smaller amounts of RAM, some