the build and execution environment.
This is very useful. For example, it allows packages built on a SuSE
8.2 system to run on a SuSE 8.1 system (this is because 8.2 has a newer
glibc; packages built against it cannot be dynamically linked against
older glibcs).
Of course, Fix packages should not directly import glibc since that is
very system-specific. Rather, they should import stdenv/stdenv.fix and
in their build scripts source in $stdenv/setup, which will setup the
right environment variables. The idea is that stdenv.fix provides the
basic C/Unix build environment (C compiler, POSIX utilities, etc.).
Note that only the ATerm package currently uses this.
svn path=/nixpkgs/trunk/; revision=203
* A solution to the library abstraction problem (i.e., if
package X needs library Y, and library Y needs library Z,
then we do not (generally) want to declare Z as a input to X
since that would break abstraction). This was not possible
under the old Nix.
svn path=/nixpkgs/trunk/; revision=150
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
build action for `system' packages (like system.fix) that have
dependencies on all packages we want to activate.
So the command sequence to switch to a new activation configuration
of the system would be:
$ fix -i .../fixdescriptors/system.fix
...
system.fix -> 89cf4713b37cc66989304abeb9ea189f
$ nix-switch 89cf4713b37cc66989304abeb9ea189f
* A nix-profile.sh script that can be included in .bashrc.
svn path=/nix/trunk/test/; revision=39
