RE: internal error: eval_thunk_selector: strange selectee 29

> Yes, I am.  I got the error several times, but when I cleaned
> everything up, it seems to have gone away -- as did the tripled
> running times (and yes, they were user/system times, not just wall
> clock).  Very puzzling.
> 
> Unfortunately, a 'make clean' removed all the evidence -- if I stumble
> over it again, I'll make a copy first.

We know of two recompilation bugs in 5.04.x & 6.0.x, both of which can
result a broken binary after making a change to a module in the program
and recompiling with --make (or in GHCi).

The first is when you switch from using -O to compiling without -O.  If
you do this, recompile the whole program from scratch.

The second we only discovered last week, and it turns out that the
current recompilation system forgets about some dependencies that it
shouldn't, and consequently will fail to recompile some things.  I don't
have a workaround yet, apart from avoiding --make.  (That sounds a bit
gloomy.  The bug has been there for ever, so it probably only strikes
very rarely).

Cheers,
        Simon