Relevant RFC: NixOS/rfcs#4

$ ag -l | xargs sed -i -e "/\"/s/’/'/g;/\"/s/‘/'/g"

This adds an argument "rev" specififying the Git commit hash. The
existing argument "rev" is renamed to "ref". The default value for
"ref" is "master". When specifying a hash, it's necessary to specify a
ref since we're not cloning the entire repository but only fetching a
specific ref.

Example usage:

  builtins.fetchgit {
    url = https://github.com/NixOS/nixpkgs.git;
    ref = "release-16.03";
    rev = "c1c0484041ab6f9c6858c8ade80a8477c9ae4442";
  };

I.e. if the local ref is more recent than tarball-ttl seconds, then
don't check the remote.

This prevents an expensive call to addToStore() in the cached case.

The package list is now cached in
~/.cache/nix/package-search.json. This gives a substantial speedup to
"nix search" queries. For example (on an SSD):

First run: (no package search cache, cold page cache)

  $ time nix search blender
  Attribute name: nixpkgs.blender
  Package name: blender
  Version: 2.78c
  Description: 3D Creation/Animation/Publishing System

  real    0m6.516s

Second run: (package search cache populated)

  $ time nix search blender
  Attribute name: nixpkgs.blender
  Package name: blender
  Version: 2.78c
  Description: 3D Creation/Animation/Publishing System

  real    0m0.143s

Note that this removes the need for a derivation symlink, so the
--drv-path and --add-drv-link flags now do nothing.

This adds about 0.1s to nix-shell runtime in the case where
bashInteractive already exists.

See discussion at https://github.com/NixOS/nixpkgs/issues/27493.

$NIX_PATH may contain elements that don't evaluate to an attrset (like
"nixos-config"), so ignore those.

BuildError denotes a permanent build failure, which is not the case
here.

Do not try to fill fd_set with fd>=FD_SETSIZE

This is UB and causes buffer overflow and crash on linux.

Update mailing list.

In particular, don't use base-64, which we don't support. (We do have
base-32 redirects for hysterical reasons.)

Also, add a test for the hashed mirror feature.

In particular, this allows it to be disabled in our tests.

use sha256 hashes in the examples

And fix a dead link.

E.g.

  $ nix path-info --json --store https://cache.nixos.org nixpkgs.thunderbird -S
  ...
      "downloadHash": "sha256:1jlixpzi225wwa0f4xdrwrqgi47ip1qpj9p06fyxxg07sfmyi4q0",
      "downloadSize": 43047620,
      "closureDownloadSize": 84745960
    }
  ]

This doesn't work in read-only mode, ensuring that operations like

  nix path-info --store https://cache.nixos.org -S nixpkgs.hello

(asking for the closure size of nixpkgs.hello in cache.nixos.org) work
when nixpkgs.hello doesn't exist in the local store.

Now you get

  [
    {
      "path": "/nix/store/fzvliz4j5xzvnd0w5zgw2l0ksqh578yk-bla",
      "valid": false
    }
  ]

On second though this was annoying. E.g. "nix log nixpkgs.hello" would
build/download Hello first, even though the log can be fetched
directly from the binary cache.

May need to revisit this.

Multi-user installer for Darwin (master edition)

Also output in the status report that the user is very silly

Starve the TTY of input to ensure this works, but provide yes to the
current installer to handle the current broken case.