$ ghc-pkg check outputs nothing $ ghc-pkg list unix /var/lib/ghc-6.12.1/package.conf.d unix-2.4.0.0 /home/alex/.ghc/x86_64-linux-6.12.1/package.conf.d "unix" appears to be in the build-depends of the "Library", but not in the build-depends of "Executable lambdabot" Adding "unix" to the second build-depends appears to fix the error (but now it complains that base is hidden). On Wed, Mar 31, 2010 at 8:48 PM, Ivan Miljenovic wrote:

On 1 April 2010 11:42, Alex Rozenshteyn wrote:

...

Main.hs:11:7: Could not find module `System.Posix.Signals': It is a member of the hidden package `unix-2.4.0.0'. Perhaps you need to add `unix' to the build-depends in your .cabal file.

Interesting, because unix _is_ listed in build-depends in the .cabal file for lambdabot.

Does "ghc-pkg check" complain about unix? Does "ghc-pkg list unix" say it's there?

...

I have a feeling this has something to do with the interaction between cabal and apt...

Highly unlikely unless there's an inconsistency in the packages on your system.

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

-- Alex R

Am Montag 05 April 2010 17:19:35 schrieb Alex Rozenshteyn:

Anyone?

"base" isn't listed among the build-depends of the executable, so the obvious thing is to add base to the build-depends and see what happens then (might also be necessary for some other packages). I'm not sure whether iterating that strategy will get lambdabot to build or it's too bit-rotted, so prepare to dive into the sources if you really want it to build.

On Wed, Mar 31, 2010 at 9:18 PM, Alex Rozenshteyn

wrote:

...

$ ghc-pkg check

outputs nothing

$ ghc-pkg list unix /var/lib/ghc-6.12.1/package.conf.d unix-2.4.0.0 /home/alex/.ghc/x86_64-linux-6.12.1/package.conf.d

"unix" appears to be in the build-depends of the "Library", but not in the build-depends of "Executable lambdabot" Adding "unix" to the second build-depends appears to fix the error (but now it complains that base is hidden).

On Wed, Mar 31, 2010 at 8:48 PM, Ivan Miljenovic <

ivan.miljenovic@gmail.com> wrote:

...

On 1 April 2010 11:42, Alex Rozenshteyn wrote:

...

Main.hs:11:7: Could not find module `System.Posix.Signals': It is a member of the hidden package `unix-2.4.0.0'. Perhaps you need to add `unix' to the build-depends in your .cabal file.

Interesting, because unix _is_ listed in build-depends in the .cabal file for lambdabot.

Does "ghc-pkg check" complain about unix? Does "ghc-pkg list unix" say it's there?

...

I have a feeling this has something to do with the interaction between

cabal

...

and apt...

Highly unlikely unless there's an inconsistency in the packages on your system.

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com

-- Alex R

Am Montag 05 April 2010 17:39:29 schrieb Alex Rozenshteyn:

I did try that; after adding a bunch of packages to the .cabal file and trying to build i get this: [ 1 of 81] Compiling Plugin.Dict.DictLookup ( Plugin/Dict/DictLookup.hs, dist/build/lambdabot/lambdabot-tmp/Plugin/Dict/DictLookup.o )

Plugin/Dict/DictLookup.hs:33:4: Ambiguous type variable `e' in the constraint: `GHC.Exception.Exception e' arising from a use of `handle' at Plugin/Dict/DictLookup.hs:33:4-42 Probable fix: add a type signature that fixes these type variable(s) cabal: Error: some packages failed to install: lambdabot-4.2.2.1 failed during the building phase. The exception was: ExitFailure 1

Looks like it was written for the old Control.Exception. You can a) change the import to import Control.OldException (handle) b) add a type signature in that line, e.g. handle (\(e :: SomeException) -> ...) if you don't know what types of exceptions to expect