(9:50:09 PM) rafl: it involves hooking into PL_check[OP_EVAL], checking if it's the string version and that your pragma is in effect
(9:50:19 PM) rafl: and replacing the ppaddr of the op
(9:50:34 PM) rafl: so that it'll prepend "use your_pragma;" to the eval string when executed
For all currently released versions of Perl (up to 5.10.0), spurious failures are reported from hints.t due to File::Copy not returning 0 when run on VMS.