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).
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 âø£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.
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
* Dockerfile: add GNU tar native dependency
`builtins.fetchTarball` requires GNU tar to be available in the $PATH in
order to unpack the fetched tarball (there is a FIXME comment for this),
which Alpine does not ship by default (it ships BusyBox tar).
* Dockerfile: add GNU bash native dependency
`nix-shell` defaults to invoking `bash` from the $PATH for the subshell.
In theory this can be overriden with the NIX_BUILD_SHELL environment
variable, but this does not work properly. `nix-shell` generates and
passes a script (`$rcFile`) to be executed by the subshell which uses
bashisms (`source` and `shopt`). Additionally, in interactive mode,
`nix-shell` passes the `--rcfile` argument to the shell, which is
another bashism.
Because `bash` is thus de-facto required, add `bash` as a native package
dependency to make it available for `nix-shell`.
