[Haskell-cafe] package question/problem

[Bertram Felgenhauer]

Galchin, Vasili wrote:
>     I am trying to "cabal install" HSQL. I am using ghc 6.8.2. I get the
> following error about a non-visible/hidden package (old-time-1.0.0.0):
> 
> vigalchin at ubuntu:~$ cabal install hsql
[snip]
> Database/HSQL.hsc:66:7:
>     Could not find module `System.Time':
>       it is a member of package old-time-1.0.0.0, which is hidden
> cabal: Error: some packages failed to install:
> hsql-1.7 failed during the building phase. The exception was:
> exit: ExitFailure 1
> vigalchin at ubuntu:~$

This happens because Cabal invokes ghc with the -hide-all-packages flag.
It then adds explicit -package flags for all packages listed as
build dependencies. (The idea is to force developers to specify all
their package's dependencies in the library's .cabal file.)

Sadly, hsql looks unmaintained.

You can try unpacking the hsql-1.7 tarball and adding the required
dependencies to the  build-depends:  field of the .cabal file.
Running 'cabal install' in the source directory will attempt to
install the package.

> What is the history of old-time package?

old-time was split out of the base package in base 3.0 (which ships
with ghc 6.8.x).

HTH,

Bertram