The first occurrence of "runtime dependencies" wasn't related to the surrounding narrative.

http://hydra.nixos.org/build/32085949

This is currently only used by the Hydra queue runner rework, but like
eff5021e it presumably will be useful
for the C++ rewrite of nix-push and
download-from-binary-cache. (@shlevy)

This is used by the Hydra queue runner, but since it may also be
useful for the C++ rewrite of nix-push, I'm putting it here.

Otherwise we might leak memory.

http://hydra.nixos.org/build/32005971

The call to tmp_number.append had its arguments mixed up. Also, JSON
does not allow a trailing "," after array/object members.

Typo fix

All other places in the script do this already, so let's be consistent.

Implement floats

The `set -e` at the top of the script causes the installation to fail to
complete if the shell profile is not writeable. Checking file existence
only is not enough.

Calling a class an API is a bit redundant...

Also, move a few free-standing functions into StoreAPI and Derivation.

Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)

"tests/lang.sh" can handle this.

For example,

  $ nix-build --hash -A nix-repl.src

will build the fixed-output derivation nix-repl.src (a fetchFromGitHub
call), but instead of *verifying* the hash given in the Nix
expression, it prints out the resulting hash, and then moves the
result to its content-addressed location in the Nix store. E.g

  build produced path ‘/nix/store/504a4k6zi69dq0yjc0bm12pa65bccxam-nix-repl-8a2f5f06-src’ with sha256 hash ‘0cjablz01i0g9smnavhf86imwx1f9mnh5flax75i615ml71gsr88’

The goal of this is to make all nix-prefetch-* scripts unnecessary: we
can just let Nix run the real thing (i.e., the corresponding fetch*
derivation).

Another example:

  $ nix-build --hash -E 'with import <nixpkgs> {}; fetchgit { url = "https://github.com/NixOS/nix.git"; sha256 = "ffffffffffffffffffffffffffffffffffffffffffffffffffff"; }'
  ...
  git revision is 9e7c1a4b
  ...
  build produced path ‘/nix/store/gmsnh9i7x4mb7pyd2ns7n3c9l90jfsi1-nix’ with sha256 hash ‘1188xb621diw89n25rifqg9lxnzpz7nj5bfh4i1y3dnis0dmc0zp’

(Having to specify a fake sha256 hash is a bit annoying...)

nix-shell shebangs were broken by 9018deab

Revert "Revert "next try for "don't abort when given unmatched '}' with 'start-condition stack underflow'. This fixes  #751"""

This reverts commit b669d3d2.

Revert "next try for "don't abort when given unmatched '}' with 'start-condition stack underflow'. This fixes  #751""

This reverts commit ed23c856. Let's
merge this *after* the 1.11.1 release.