id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	difficulty	ghcversion	platform
680	Spec should define the interpretation of the library and includes and search dirs	duncan		"See http://hackage.haskell.org/trac/ghc/ticket/3930

The Cabal spec should say how to interpret the `extra-libraries` and `library-dirs` fields in the installed package info. Specifically how this information is interpreted in relation to package dependencies which may also specify libraries and search paths.

The interpretation should be that all the `extra-libraries` required by a installed package should be found in `library-dirs` given in that installed package info, or in the ""standard"" system linker path (as used by the standard system linker). That is, the `library-dirs` of dependent packages should not be used.

For example:
{{{
-- installed package gtk:
extra-libraries: gtk-x11-2.0
library-dirs:
depends: glib

-- installed package glib:
extra-libraries: glib-2.0
library-dirs: /opt/local/lib
}}}

We presume here that `/opt/local/lib` is not on the standard linker path. Then we should only look for the `gtk-x11-2.0` library on the paths specified in the gtk package, which in this case is empty, so that means only on the system linker path. If `gtk-x11-2.0` is in fact only in `/opt/local/lib` then this will and should fail. We should not use the library dirs of the `glib` package to find the libraries of the `gtk` package.

The correct information for the above example would be to list `library-dirs: /opt/local/lib` for the gtk package also."	enhancement	new	normal		Cabal specification		normal				unknown