Failed extracting executableConfigs when a cabal file is present.

[gcharnock]

I've tried the following steps

$git clone https://github.com/kazu-yamamoto/ghc-mod.git
$cd ghc-mod/
$cabal sandbox init
$cabal install
$ghc-mod

ghc-mod works fine with random haskell files, but errors with the following message:

extractField: failed extracting executableConfigs from input, input contained `executableConfigs'? False

When run anywhere managed by a cabal file. This includes the ghc-mod directory just checked out. Just to be sure I was running the right command, I also tried:

$dist/dist-sandbox-b71143f6/build/ghc-mod/ghc-mod

And got the same result.

$cabal --version
cabal-install version 1.21.0.0
using version 1.21.0.0 of the Cabal library

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.8.3

[DanielG]

Looks like cabal 1.21 changed the LocalBuildInfo datatype again. Since it hasn't actually been released yet it's not supported right now. Are you using a Cabal/cabal-install development snapshot?

[DanielG]

Could you post you dist/setup-config file (on gist or something since it's huge), it's generated by cabal configure.

[alanz]

Did you cabal configure before trying it?

[gcharnock]

I completely forgot that I'd installed a patched cabal a few weeks back in order to try out ghcjs. When I downgraded things seem to be working again.

(gist, in case you still wanted it. https://gist.github.com/gcharnock/5390c9448e8f5981b164)

[DanielG]

Good thing you gave us a heads up to the upcoming incompatibility though :p