This fixes an assertion failure in "assert(goal);" in
Worker::waitForInput() after a substitution goal is cancelled by the
termination of another goal. The problem was the line

  //worker.childTerminated(shared_from_this()); // FIXME

in the SubstitutionGoal destructor. This was disabled because
shared_from_this() obviously doesn't work from a destructor. So we now
use a real pointer for object identity.

These don't support regex_replace either.

This reverts commit f32c6ed8. It
breaks the RPM builds because Nixpkgs's rpmBuild function only copies
in the .tar.gz file.

These don't support regex_replace.

http://hydra.nixos.org/build/39363999
http://hydra.nixos.org/build/39363981

The implementation of "partition" in Nixpkgs is O(n^2) (because of the
use of ++), and for some reason was causing stack overflows in
multi-threaded evaluation (not sure why).

This reduces "nix-env -qa --drv-path" runtime by 0.197s and memory
usage by 298 MiB (in non-Boehm mode).

Also, factor out JSON generation from value-to-json.{cc,hh}, and
support producing indented JSON.

Normally it's impossible to take a reference to the function passed to
callFunction, so some callers (e.g. ExprApp::eval) allocate that value
on the stack. For functors, a reference to the functor itself may be
kept, so we need to have it on the heap.

Fixes #1045

The inner lambda was returning a SQLite-internal char * rather than a
std::string, leading to Hydra errors liks

  Caught exception in Hydra::Controller::Root->narinfo "path ‘ø˜£â€™ is not in the Nix store at /nix/store/6mvvyb8fgwj23miyal5mdr8ik4ixk15w-hydra-0.1.1234.abcdef/libexec/hydra/lib/Hydra/Controller/Root.pm line 352."

That is, unless --file is specified, the Nix search path is
synthesized into an attribute set. Thus you can say

  $ nix build nixpkgs.hello

assuming $NIX_PATH contains an entry of the form "nixpkgs=...". This
is more verbose than

  $ nix build hello

but is less ambiguous.

For example, you can now say:

  configureFlags = "--prefix=${placeholder "out"} --includedir=${placeholder "dev"}";

The strings returned by the ‘placeholder’ builtin are replaced at
build time by the actual store paths corresponding to the specified
outputs.

Previously, you had to work around the inability to self-reference by doing stuff like:

  preConfigure = ''
    configureFlags+=" --prefix $out --includedir=$dev"
  '';

or rely on ad-hoc variable interpolation semantics in Autoconf or Make
(e.g. --prefix=\$(out)), which doesn't always work.

Allow contexted strings in replaceStrings

Otherwise in particular https://cache.nixos.org won't work in the
daemon.

This was only used by nix-push.

Let's step in line with time and document more realistic values.

This makes us more robust against 500 errors from CloudFront or S3
(assuming the 500 error isn't cached by CloudFront...).

This allows such paths to be imported without signatures.

This makes it easier to create a diverted store, i.e.

  NIX_REMOTE="local?root=/tmp/root"

instead of

  NIX_REMOTE="local?real=/tmp/root/nix/store&state=/tmp/root/nix/var/nix" NIX_LOG_DIR=/tmp/root/nix/var/log

This variable has no reason to exist, given $NIX_STATE_DIR.

Nuke nix-push.

Rarely used, nix copy replaces it.

We have BinaryCacheStore now

Was added in 2006 to "measure the cost of the Nix approach".

Given that it uses /usr/bin/perl, I think this is safe to remove.

Remove nix-install-package.