What version of perl did you test that with? On

This is perl, v5.10.1 (*) built for i686-linux-gnu-thread-multi
(with 40 registered patches, see perl -V for more detail)
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(it's the default system perl from latest Ubuntu) your example doesn't seem to be working for me:

$ perl -E 'use lib sub {say "Using $_[1]"; sub {$_ = "1;"; 0}}, sub {d
+ie}; use Blah; say "Hi!";'
Using Blah.pm
Blah.pm did not return a true value at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
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