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.
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| .. | ||
| flake | ||
| primops | ||
| attr-path.cc | ||
| attr-path.hh | ||
| attr-set.cc | ||
| attr-set.hh | ||
| common-eval-args.cc | ||
| common-eval-args.hh | ||
| eval-cache.cc | ||
| eval-cache.hh | ||
| eval-inline.hh | ||
| eval.cc | ||
| eval.hh | ||
| fetchurl.nix | ||
| function-trace.cc | ||
| function-trace.hh | ||
| get-drvs.cc | ||
| get-drvs.hh | ||
| imported-drv-to-derivation.nix | ||
| json-to-value.cc | ||
| json-to-value.hh | ||
| lexer.l | ||
| local.mk | ||
| nix-expr.pc.in | ||
| nixexpr.cc | ||
| nixexpr.hh | ||
| parser.y | ||
| primops.cc | ||
| primops.hh | ||
| symbol-table.hh | ||
| value-to-json.cc | ||
| value-to-json.hh | ||
| value-to-xml.cc | ||
| value-to-xml.hh | ||
| value.hh | ||