lix/src
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
..
bin2c * Sync with the trunk. 2010-04-20 09:20:29 +00:00
boost * Install some headers in the right location. 2009-03-05 14:57:50 +00:00
bsdiff-4.3 * Quick hack around one of the pathological cases in bsdiff 2010-11-29 17:07:04 +00:00
libexpr * Support multiple outputs. A derivation can declare multiple outputs 2011-07-18 23:31:03 +00:00
libmain Add support for the build-timeout' and --timeout' options. 2011-06-30 15:19:13 +00:00
libstore Add support for the build-timeout' and --timeout' options. 2011-06-30 15:19:13 +00:00
libutil * Sync with the trunk. 2011-02-09 12:25:53 +00:00
nix-env * nix-env -ub' (--prebuilt-only') didn't really work because it 2011-04-11 16:27:05 +00:00
nix-hash * Store the size of a store path in the database (to be precise, the 2010-11-16 17:11:46 +00:00
nix-instantiate * Sync with the trunk. 2010-11-16 12:49:47 +00:00
nix-log2xml * Emit warning='1' or error='1' attributes for lines marked as 2010-03-05 12:54:58 +00:00
nix-setuid-helper * Drop the dependency on the ATerm library. 2010-04-19 14:51:58 +00:00
nix-store * Add an operation `nix-store -q --size'. 2010-11-17 12:40:52 +00:00
nix-worker * Propagate the "100" exit status for failed builds through the Nix 2010-12-17 11:28:26 +00:00
Makefile.am * Drop the dependency on the ATerm library. 2010-04-19 14:51:58 +00:00