System.Console.CmdArgs.Implicit, unexpected flag (end): Text about cmdargs HOT 12 CLOSED

Hmm, weird. Can you give me a small example that fails? I'm on Windows, which might give us another viewpoint. Are you using the same version of GHC and cmdargs in both cases?

from cmdargs.

Here is a simple test case, both machines have identical package versions and are using GHC 7.8.3.

Main.hs

module Sample where
import System.Console.CmdArgs
import Data.Text

data Sample = Sample {hello :: Text}
              deriving (Show, Data, Typeable)

sample = Sample{hello = ""}

main = print =<< cmdArgs sample

On OSX:

runhaskell Main.hs
Sample {hello = ""}

On Ubuntu 14.10:

runhaskell Main.hs 
Main.hs: System.Console.CmdArgs.Implicit, unexpected flag (hello): Text

from cmdargs.

Replacing Text with String is one workaround. The following works on both Ubuntu and OSX:

module Sample where
import System.Console.CmdArgs
import Data.Text

data Sample = Sample {hello :: String}
              deriving (Show, Data, Typeable)

sample = Sample{hello = ""}

main = print =<< cmdArgs sample

runhaskell Main.hs
Sample {hello = ""}

It would be greatly preferred, of course, to not have to use such a workaround though....

from cmdargs.

On Ubuntu 14.04.1 with ghc 7.6.3, runhaskell Main.hs works, but on Ubuntu 14.10 with ghc 7.8.3 it does not.

from cmdargs.

This seems like a Cabal Sandbox issue. On both the Ubuntu 14.04.1 with ghc 7.6.3 and Ubuntu 14.10 with ghc 7.8.3 this sample project fails, with cabal run yielding the error and runhaskell working just fine. See test.sh to reproduce.

from cmdargs.

This is cabal's fault.

from cmdargs.

OK, thanks for figuring this out, I'll bear it in mind if people get similar bugs in future.

from cmdargs.

I reproduced the error with GHC 7.8.4, cmdargs-0.10.14, and text-1.1.0.0 when looking into the cabal issue.

from cmdargs.

@grayjay - do you still believe this is a Cabal error?

from cmdargs.

I don't think so. I got the same error with cabal and runhaskell. It seemed to depend on the version of text.

from cmdargs.

Does it go away with the latest version of text?

from cmdargs.

Yes, there was no error with text-1.2.2.1.

from cmdargs.