Trouble recompiling ksh package with the AUDIT option.

Issue

Reproducer:

• downloaded the ksh src rpm
• install it
• extract src.tgz archive
• edit /root/rpmbuild/SOURCES/src/cmd/ksh93/Makefile and set value:

SHOPT_AUDIT == 1

• create new tgz src file ast-ksh.2010-06-21.tgz with the update
• update the ksh spec file with a new version number
• build the rpm package with rpmbuild
• install the new package

Result:

• the AUDIT option did not get compiled in

# print ${.sh.version}
Version JM 93t+ 2010-06-21

Expected result:

• compiled in AUDIT option

# print ${.sh.version}
Version AJM 93t+ 2010-06-21

How can we recompile the ksh src package with the AUDIT flag?
The audit flag was present in ksh shipped with RHEL 5.