the values of INST_DRV and INST_TOP. You can also enable various
build flags. These are explained in the makefiles.
+Note that it is generally not a good idea to try to build a perl with
+INST_DRV and INST_TOP set to a path that already exists from a previous
+build. In particular, this may cause problems with the
+lib/ExtUtils/t/Embed.t test, which attempts to build a test program and
+may end up building against the installed perl's lib/CORE directory rather
+than the one being tested.
+
You will have to make sure that CCTYPE is set correctly and that
CCHOME points to wherever you installed your compiler.