Another installing Yesod on Ubuntu difficulty

Question

Looking around StackOverflow I see a bunch of similar problems, but each about a specific library.

Here's mine :

When trying to run :

cabal install yesod

I get

Resolving dependencies...
Configuring yaml-0.8.7...
Building yaml-0.8.7...
Preprocessing library yaml-0.8.7...

Data/Yaml/Parser.hs:15:8:
    Could not find module `Data.Conduit.Lift'
    Perhaps you meant
      Data.Conduit.List (from conduit-1.0.8)
      Data.Conduit.List (needs flag -package conduit-1.0.5.1)
      Data.Conduit.Text (needs flag -package conduit-1.0.5.1)
    Use -v to see a list of the files searched for.
Failed to install yaml-0.8.7
Configuring yesod-core-1.2.10...
Building yesod-core-1.2.10...
Preprocessing library yesod-core-1.2.10...

Yesod/Core/Json.hs:47:8:
    Could not find module `Data.Conduit.Lift'
    Perhaps you meant
      Data.Conduit.List (from conduit-1.0.8)
      Data.Conduit.List (needs flag -package conduit-1.0.5.1)
      Data.Conduit.Text (needs flag -package conduit-1.0.5.1)
    Use -v to see a list of the files searched for.
Failed to install yesod-core-1.2.10
cabal: Error: some packages failed to install:
yaml-0.8.7 failed during the building phase. The exception was:
ExitFailure 1
yesod-1.2.5.2 depends on yesod-core-1.2.10 which failed to install.
yesod-auth-1.3.0.2 depends on yesod-core-1.2.10 which failed to install.
yesod-core-1.2.10 failed during the building phase. The exception was:
ExitFailure 1
yesod-form-1.3.8.1 depends on yesod-core-1.2.10 which failed to install.
yesod-persistent-1.2.2.2 depends on yesod-core-1.2.10 which failed to install.

Is something broken in Hackage or is this just on my machine?

Answer 1

You're trying to install a version of yaml that doesn't have a strict enough lower bound on conduit. There is a newer version already on Hackage. It looks like you haven't run cabal update.