forked from lix-project/lix
5cd72598fe
Impure derivations are derivations that can produce a different result
every time they're built. Example:
stdenv.mkDerivation {
name = "impure";
__impure = true; # marks this derivation as impure
outputHashAlgo = "sha256";
outputHashMode = "recursive";
buildCommand = "date > $out";
};
Some important characteristics:
* This requires the 'impure-derivations' experimental feature.
* Impure derivations are not "cached". Thus, running "nix-build" on
the example above multiple times will cause a rebuild every time.
* They are implemented similar to CA derivations, i.e. the output is
moved to a content-addressed path in the store. The difference is
that we don't register a realisation in the Nix database.
* Pure derivations are not allowed to depend on impure derivations. In
the future fixed-output derivations will be allowed to depend on
impure derivations, thus forming an "impurity barrier" in the
dependency graph.
* When sandboxing is enabled, impure derivations can access the
network in the same way as fixed-output derivations. In relaxed
sandboxing mode, they can access the local filesystem.
|
||
|---|---|---|
| .. | ||
| build-remote | ||
| libcmd | ||
| libexpr | ||
| libfetchers | ||
| libmain | ||
| libstore | ||
| libutil | ||
| nix | ||
| nix-build | ||
| nix-channel | ||
| nix-collect-garbage | ||
| nix-copy-closure | ||
| nix-env | ||
| nix-instantiate | ||
| nix-store | ||
| resolve-system-dependencies | ||
| toml11 | ||