Find a file
Eelco Dolstra d329c3ea9d * Support multiple outputs. A derivation can declare multiple outputs
by setting the ‘outputs’ attribute.  For example:

    stdenv.mkDerivation {
      name = "aterm-2.5";

      src = ...;

      outputs = [ "out" "tools" "dev" ];

      configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include";
    }

  This derivation creates three outputs, named like this:

    /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5
    /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools
    /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev

  That is, the symbolic name of the output is suffixed to the store
  path (except for the ‘out’ output).  Each path is passed to the
  builder through the corresponding environment variable, e.g.,
  ${tools}.

  The main reason for multiple outputs is to allow parts of a package
  to be distributed and garbage-collected separately.  For instance,
  most packages depend on Glibc for its libraries, but don't need its
  header files.  If these are separated into different store paths,
  then a package that depends on the Glibc libraries only causes the
  libraries and not the headers to be downloaded.

  The main problem with multiple outputs is that if one output exists
  while the others have been garbage-collected (or never downloaded in
  the first place), and we want to rebuild the other outputs, then
  this isn't possible because we can't clobber a valid output (it
  might be in active use).  This currently gives an error message
  like:

    error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths

  There are two solutions: 1) Do the build in a chroot.  Then we don't
  need to overwrite the existing path.  2) Use hash rewriting (see the
  ASE-2005 paper).  Scary but it should work.

  This is not finished yet.  There is not yet an easy way to refer to
  non-default outputs in Nix expressions.  Also, mutually recursive
  outputs aren't detected yet and cause the garbage collector to
  crash.
2011-07-18 23:31:03 +00:00
corepkgs * nix-push: no need to compute the NAR hash, since the Nix database 2010-11-17 12:51:54 +00:00
doc * Allow a default value in attribute selection by writing 2011-07-13 12:19:57 +00:00
externals * Propagate the CC setting. 2011-02-05 16:40:15 +00:00
misc * Allow a default value in attribute selection by writing 2011-07-13 12:19:57 +00:00
scripts * Fix concurrency issues in download-using-manifests' handling of the 2011-07-13 14:05:54 +00:00
src * Support multiple outputs. A derivation can declare multiple outputs 2011-07-18 23:31:03 +00:00
tests * Allow attribute names to be strings. Based on the 2011-07-13 15:53:24 +00:00
.gitignore Add `.gitignore'. 2010-02-10 15:55:46 +00:00
AUTHORS * Put something in here. 2004-11-07 20:30:02 +00:00
bootstrap.sh * Use SQLite 3.7.0's write-ahead logging (WAL mode). This is a lot 2010-08-04 17:35:59 +00:00
ChangeLog * Autoconf / Automake configuration and building. 2003-04-04 16:14:56 +00:00
configure.ac * Show the default for --with-store-dir (Nix/211). 2011-07-13 15:57:44 +00:00
COPYING * Change this to LGPL to keep the government happy. 2006-04-25 16:41:06 +00:00
INSTALL * Autoconf / Automake configuration and building. 2003-04-04 16:14:56 +00:00
Makefile.am * Install config.h. 2010-10-26 10:47:02 +00:00
nix.conf.example * Document --cores in the manual. 2010-08-17 07:22:05 +00:00
nix.spec.in * Urgh. 2008-11-20 16:42:52 +00:00
README * Install documentation in $(docdir) (i.e. share/doc/nix). 2008-11-19 13:19:09 +00:00
release.nix 2011-04-11 10:23:15 +00:00
substitute.mk * configure: detect whether DBD::SQLite is present. If necessary the 2011-04-11 10:13:53 +00:00
version * Bump the version number. 2010-08-17 15:39:35 +00:00

Nix is a purely functional package manager.  For installation and
usage instructions, please read the manual, which can be found in
`docs/manual/manual.html', and additionally at the Nix website at
<http://nixos.org/>.


Acknowledgments

This product includes software developed by the OpenSSL Project for
use in the OpenSSL Toolkit (http://www.OpenSSL.org/).