On Wed, Oct 22, 2003 at 12:23:51PM +0100, Simon Marlow wrote:

...

This is on ghc-6.0.1 installed from RPM on Red Hat Linux release 7.3 (Valhalla), i-386 unknown.

Probably, you can reduce the example several times more.

ghci Main +RTS -M1m -RTS

..> : Main ..> main ... (<interactive>: internal error: thread_stack: weird activation record found on stack: 1564 Please report this as a bug to glasgow-haskell-bugs@haskell.org ..

Probably, the interpreter manages memory in a wrong way. Can you reproduce the effect?

That's a bug, thanks for the report.

Just out of interest, why are you passing the -M1m flag to ghci? This sets a bound of 1M on GHC's memory, and causes the compacting GC to kick in when this bound is approached (which will be almost immediately). The bug was in the compacting garbage collector, which explains why it hasn't shown up until now.

I was deliberately passing various -Mxx flags to ghci because wanted to find where this simple program manages wrongly the memory. I did this `instead' of increasing the list [1..n] in the example. And I started this test after DoCon's real test crashed in ghci, within reasonable memory, somewhat about -M40m. And generally, it is desirable for the tool to allow, if the user ask this, doing large computation in posibly small space, even by spending much more time. The smaller space suffices, the more flexy and nicer the tool is -- this is my idea. With kind regards, ------------------ Serge Mechveliani mechvel@botik.ru