First, what's with env all over the place? Not only is it useless, I think it's actually hurting here. You're asking it to locate the program LD_LIBRARY_PATH=/my/lib.

Secondly, perlrun doesn't mention
#!/bin/sh -- -*- perl -*-
but it does mention
#!/bin/sh -- # -*- perl -*-
Unfortunately, that doesn't work with my sh.

However, it's easy to work around that using -x.

#!/bin/sh
eval 'MYTESTVAR=/my/lib exec /usr/bin/perl -x -S $0 ${1+"$@"}'
   if $runningUnderSomeShell;

#!perl
print "[", $ENV{MYTESTVAR}, "]\n";
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