cabal should detect when a new version of a library is installed

[bos]

(Imported from Trac #110, reported by guest on 2007-02-15)

I have a program A that uses library B.

For A i type:

runhaskell Setup.hs configure
runhaskell Setup.hs build

The binaries are created. However, A uses B and when i then change the library B:

echo "improved code" >> Main.hs
runhaskell Setup.hs configure
runhaskell Setup.hs build
runhaskell Setup.hs install

The library is installed fine, but recompiling A does not work, because Cabal only seems to stat

the executable, and does not check, whether a library that the program depends on, maybe has a newer timestamp.

So one always has to runhaskell Setup.hs clean the workspace if not sure if something in the libs changed (in a script ...)

[bos]

(Imported comment by @dcoutts on 2007-02-15)

Currently recompilation checking is deferred to ghc and it does not check packages at the moment. See http://hackage.haskell.org/trac/ghc/ticket/1372

[bos]

(Imported comment by @dcoutts on 2007-09-12)

For ghc this is now done by ghc --make itself (I think since 6.8 or 6.10).

The more general problem is the same as always, the lack of a proper dep system #15.