[Agda] Warning: hashable-1.2.0.x has serious performance bugs

[Martin Escardo]

This explains a question I asked privately to you before, where I 
reported that Agda in a high-end desktop made this year ran at the same 
speed as in a low-end netbook made in 2008.

Question: can you be more precise regarding what we have to do to avoid 
this problem? (This is not urgent: I made the desktop run 9x faster by 
copying the .cabal tree from the netbook to the desktop, as I told you.)

Thanks,
Martin

On 12/07/13 16:52, Andreas Abel wrote:
> When you compile Agda, make sure it uses hashable-1.1.2.x and not the
> newer 1.2.0.x version (which cabal automatically pulls if the choice is
> not constrained).
>
> With hashable-1.2.0.x, Agda is 10x slower!
>
> The newest darcs version asks for hashable < 1.2, so
>
>    cabal install
>
> might not work out of the box, you might have to clean out newer
> versions of hashable and reinstall packages that used hashable-1.2.0.x,
> like the hashtables package.
>
>    cabal configure -v
>
> should show you which version of the packages are picked for compilation.
>
> Cheers,
> Andreas
>