Turns out that in Nixpkgs, derivation is actually called without a
‘name’ argument in some places :-(

For example:

  error: `tail' called on an empty list, at
    /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/ex-2/default.nix:13:7

This allows error messages like:

  error: the anonymous function at `/etc/nixos/configuration.nix:1:1'
    called without required argument `foo', at
    `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/lib/modules.nix:77:59'

From https://github.com/NixOS/nix/pull/236

While running Python 3’s test suite, we noticed that on some systems
/dev/pts/ptmx is created with permissions 0 (that’s the case with my
Nixpkgs-originating 3.0.43 kernel, but someone with a Debian-originating
3.10-3 reported not having this problem.)

There’s still the problem that people without
CONFIG_DEVPTS_MULTIPLE_INSTANCES=y are screwed (as noted in build.cc),
but I don’t see how we could work around it.

The newEnv variable was accessed (via the dynamicEnv) pointer after it
had gone out of scope.

Fixes #234.

It will delete all generations older than the specified number of days.

If derivation declares multiple outputs and first (default) output
if not "out", then "nix-instantiate" calls return path with output
names appended after "!". Than suffix must be stripped before
ant path checks are done.

Since the addition of build-max-log-size, a call to
handleChildOutput() can result in cancellation of a goal.  This
invalidated the "j" iterator in the waitForInput() loop, even though
it was still used afterwards.  Likewise for the maxSilentTime
handling.

Probably fixes #231.  At least it gets rid of the valgrind warnings.

Issue #231.

Ludo reported this error:

  unexpected Nix daemon error: boost::too_few_args: format-string refered to more arguments than were passed

coming from this line:

  printMsg(lvlError, run.program + ": " + string(err, 0, p));

The problem here is that the string ends up implicitly converted to a
Boost format() object, so % characters are treated specially.  I
always assumed (wrongly) that strings are converted to a format object
that outputs the string as-is.

Since this assumption appears in several places that may be hard to
grep for, I've added some C++ type hackery to ensures that the right
thing happens.  So you don't have to worry about % in statements like

  printMsg(lvlError, "foo: " + s);

or

  throw Error("foo: " + s);

The daemon now creates /dev deterministically (thanks!).  However, it
expects /dev/kvm to be present.

The patch below restricts that requirement (1) to Linux-based systems,
and (2) to systems where /dev/kvm already exists.

I’m not sure about the way to handle (2).  We could special-case
/dev/kvm and create it (instead of bind-mounting it) in the chroot, so
it’s always available; however, it wouldn’t help much since most likely,
if /dev/kvm missing, then KVM support is missing.

Currently, clients cannot recover from an isValidPath RPC with an
invalid path parameter because the daemon closes the connection when
that happens.

More precisely:

  1. in performOp, wopIsValidPath case, ‘readStorePath’ raises an
     ‘Error’ exception;

  2. that exception is caught by the handler in ‘processConnection’;

  3. the handler determines errorAllowed == false, and thus exits after
     sending the message.

This last part is fixed by calling ‘startWork’ early on, as in the patch
below.

The same reasoning could be applied to all the RPCs that take one or
more store paths as inputs, but isValidPath is, by definition, likely to
be passed invalid paths in the first place, so it’s important for this
one to allow recovery.

Fixes #225.

Since the meta attributes were not sorted, attribute lookup could
fail, leading to package priorities and active flags not working
correctly.

Broken since 0f24400d.