Typo
mkList: Scrub better

Clearing v.app.right was not enough, because the length field of a
list only takes 32 bits, so the most significant 32 bits of v.app.left
(a.k.a. v.thunk.env) would remain. This could cause Boehm GC to
interpret it as a valid pointer.

This change reduces maximum RSS for evaluating the ‘tested’ job in
nixos/release-small.nix from 1.33 GiB to 0.80 GiB, and runtime by
about 8%.
Improved error message when encountering unsupported file types

Fixes #269.
nix-copy-closure: Use strict
Remove unused @sshOpts flag

Closes #300.
nix-channel --add: Validate URL / channel ID

Fixes #369.
Remove redundant space in usage errors
nix-channel: Add --rollback flag

Fixes #368.
nix-store -q: Check for conflicting flags

Fixes #364.
binary download: Use $NIX_CURL_FLAGS

As in https://github.com/NixOS/nixpkgs/blob/5c0816567d6b99bd2ef7c8ae5744f80a6a0372c4/pkgs/build-support/fetchurl/builder.sh#L17
Merge pull request #372 from wmertens/patch-4

binary download: Use $NIX_CURL_FLAGS
Revert "binary download: Use $NIX_CURL_FLAGS"

This reverts commit bc4795919afac59af8f27d3c1f26ab404330f718. It
breaks the build:

  http://hydra.nixos.org/build/15860847
Fix nix-copy-closure --from

http://hydra.nixos.org/build/15885652
Export realiseContext in libnixexpr

Useful for importNative plugins
Drop support for pre-c++11 compilers.

In particular, gcc 4.6's std::exception::~exception has an exception
specification in c++0x mode, which requires us to use that deprecated
feature in nix (and led to breakage after some recent changes that were
valid c++11).

nix already uses several c++11 features and gcc 4.7 has been around for
over 2 years.
Improve printing of ASTs
Revert "Drop support for pre-c++11 compilers."

The breakage this fixed can be worked around without removing support.

This reverts commit 84a13dc576496f1227665259c61f86184f452f51.
Fix build on gcc < 4.7
Temporarily disable darwin builds while hydra's darwin is borked
Merge pull request #380 from shlevy/temp-disable-darwin

Temporarily disable darwin builds while hydra's darwin is borked