[xmonad] is there a way to build xmonad-contrib 0.9.2 on a system with ghc 7.4.1?

[Brandon Allbery]

On Thu, Jun 28, 2012 at 2:11 PM, Lara Michaels
<laramichaels1978 at yahoo.com>wrote:

> I would like to install xmonad 0.9.2 (which worked fine for me) on my
> Ubuntu 12.04 system (GHC 7.4.1).
>

If you're having problems with 0.10, perhaps we should be examining the
diffs between the two to see what changed and why. (Although "why" isn't
always explained; not all programmers comment or document as well as they
should.)


> XMonad/Layout/MouseResizableTile.hs:182:17:
>     Could not deduce (Eq t) arising from the literal `0'
>     from the context (Num t)
>       bound by the type signature for
>                  replaceAtPos :: Num t => [Rational] -> t -> Rational ->
> [Rational]
>       at XMonad/Layout/MouseResizableTile.hs:(182,1)-(185,61)
>     Possible fix:
>       add (Eq t) to the context of
>

It's telling you exactly how to fix it.

Num used to imply Eq and Show, but no longer does; as such, those
constraints may need to be added in some places where pre-7.2 compiled
things without error.  In this case we don't need Show but do need Eq.

    cabal unpack xmonad-contrib-0.9.2
    vi -n +182 XMonad/Layout/MouseResizableTile.c
    # or use your favorite editor to change "Num t =>" to "(Num t, Eq t) =>"
    cabal install # no package name here; it will build and install the
package in the current directory

-- 
brandon s allbery                                      allbery.b at gmail.com
wandering unix systems administrator (available)     (412) 475-9364 vm/sms
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