I wonder if perl might have died from a fatal signal (like SIGSEGV), but your shell somehow doesn't report this? You can find this out by echoing the $? shell variable immediately after running the program from the shell. (This is for unix of course.)

You mention that the script uses much memory. If the system runs out of memory, you may get a fatal signal instead of a proper error message from perl. Also, you can get a signal if the reference counting MM deallocates a long list: an example is perl -we '$x = [$x] for 0 .. 100_000; warn 1; $x = (); warn 2;' but you may have to adjust the number 100_000 for your system.

If that's not the problem, then I guess you don't give enough information about the issue. You could try posting the script or even a simplified (non-functional) script that produces the same error.