$ echo "Can't modify reference constructor in lvalue subroutine return
+"|splain
Can't modify reference constructor in lvalue subroutine return (#1)
    (F) You aren't allowed to assign to the item indicated, or otherwi
+se try
    to change it, such as with an auto-increment.
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I suppose your tie is loading too much magic onto $dummy ... but this would be a runtime error not compilation like you indicated(?)

Please try to give a concise sample reproducing your problem, I'm not motivated to dig into your module to do the binary debugging search for you. ;-)

... and please name concrete Perl version numbers failing.