cabal doesn't explore the none manual flags very well

Andres Löh andres at
Wed Mar 12 17:55:09 UTC 2014

Hi there.

> i'm repeatedly seeing many examples where a Manual : False flag is used to
> encode an "OR" in the cabal configuration, and where cabal "gives up" on
> finding the "right" build plan i know it can find if it has to flip the flag
> in a dependency its building...
> Is this a known issue? how can i mitigate it?

It wasn't really known to me until recently.

I'm currently looking at this issue, but I unfortunately don't have
much time to work on it. As a workaround, it might help to add a
package for which a suboptimal version is chosen because the flag is
set to the wrong value explicitly as a target on the command line.


Andres Löh, Haskell Consultant
Well-Typed LLP,

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