The problem of transitive imports needs to be adressed, though, as
evidenced by, e.g., the descriptor for pan. That is, if C depends
on library B, and B depends on library A, then C also depends on
library A. However, this breaks modularity: C should not have to
declare a dependency on A explicitly.
The solution is to have B re-export A, e.g., by creating symlinks
from B to the files in A.
svn path=/nixpkgs/trunk/; revision=68
* Conditionals and variables in Fix expressions. This allows, e.g.,
Descr(
[ Bind("pkgId", "subversion-0.21.0")
, Bind("httpsClient", Bool(True))
, Bind("httpServer", Bool(True))
, Bind("ssl", If(Var("httpsClient"), Fix("./openssl-0.9.7b.fix"), ""))
, Bind("httpd", If(Var("httpServer"), Fix("./httpd-2.0.45.fix"), ""))
...
])
which introduces domain feature variables httpsClient and httpServer
(i.e., whether Subversion is built with https client and webdav
server support); the values of the variables influences package
dependencies and the build scripts.
The next step is to allow that packages can express constraints on
each other. E.g., StrategoXT is dependent on an ATerm library with
the "gcc" variant enabled. In fact, this may cause several
Nix instantiations to be created from a single Fix descriptor. If
possible, Fix should try to find the least set of instantiations
that obeys the constraints.
svn path=/nix/trunk/test/; revision=53
* Added descriptors for gtkspell and its support package pspell.
Gtkspell is an optional dependency of Pan, so we should add the
ability to nix-instantiate to instantiate variants of a package
based on a selection of features.
svn path=/nix/trunk/test/; revision=16
