[Hat] Fwd: buggy sorting function

[Colin Runciman]

Bob,

>> When you hit ^C (once?) did you wait for the .hat file to be  patched up
>> after the signal was caught?
>
>
> I didn't, this is a ghc on Mac bug -- ctrl-C doesn't work, you have 
> to send it a kill -9 from elsewhere... I just forgot that.  So is the 
> likely cause that the file had not been flushed to disk?

It is more than just flushing an ordinary file buffer.  Hat has its own
fancy buffering system to minimise the number of updates to the trace
file. Further, the trace has to be updated so that all expressions in
mid-evaluation have "interrupted" as their result, and the trace must
record the point of interruption.

None of this can happen after a violent "kill -9".  The program just
stops dead.  So does the trace.  Hence the complaint from the
trace-processing tools.

Colin