I accidentally the Prelude

Yitzchak Gale gale at sefer.org
Wed Mar 3 08:42:44 EST 2010

I wrote:
>> I was suggesting that whenever the Prelude fails to load,
>> the error message should contain that hint.

> hmm, I'll think about that. Is it not enough to see a compilation error
> pointing to the file Prelude.hs?

Seems obvious in the context of this thread. But not being in
the middle of reading the thread, I am certain that this hint
would save me a lot of time and anguish. And it clearly
would have done the same for Josef.

> it's probably not that bad, actually:
> $ ghc --make hello
> [1 of 2] Compiling Prelude          ( Prelude.hs, Prelude.o )
> [2 of 2] Compiling Main             ( hello.hs, hello.o )
> hello.hs:1:8: Not in scope: `putStr'
> You can pretty clearly see what happened there.

When something goes wrong with a basic system
component like the Prelude, the natural
reaction of most people is panic. I've been getting file
system corruption lately on a removable hard disk - could
it be that? Did I cause this when I moved around some
system directories the other day? Are my different copies
of GHC getting mixed up with each other's files?

It's hard to overestimate how much a soothing message
from GHC is appreciated in that kind of situation.


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