From aabf5c86c9df1b4e1616a4cf06ee14a6edf2e5e1 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 16 Oct 2019 17:45:09 +0200 Subject: Add experimental-features setting Experimental features are now opt-in. There is currently one experimental feature: "nix-command" (which enables the "nix" command. This will allow us to merge experimental features more quickly, without committing to supporting them indefinitely. Typical usage: $ nix build --experimental-features 'nix-command flakes' nixpkgs#hello (cherry picked from commit 8e478c234100cf03ea1b777d4bd42a9be7be9e8c, without the "flakes" feature) --- src/libstore/globals.cc | 7 +++++++ src/libstore/globals.hh | 5 +++++ src/nix/main.cc | 2 ++ tests/init.sh | 1 + 4 files changed, 15 insertions(+) diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc index 1c2c08715..249c36673 100644 --- a/src/libstore/globals.cc +++ b/src/libstore/globals.cc @@ -105,6 +105,13 @@ StringSet Settings::getDefaultSystemFeatures() return features; } +void Settings::requireExperimentalFeature(const std::string & name) +{ + auto & f = experimentalFeatures.get(); + if (std::find(f.begin(), f.end(), name) == f.end()) + throw Error("experimental Nix feature '%s' is disabled", name); +} + const string nixVersion = PACKAGE_VERSION; template<> void BaseSetting::set(const std::string & str) diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh index ab1c09aa2..1221e4db7 100644 --- a/src/libstore/globals.hh +++ b/src/libstore/globals.hh @@ -353,6 +353,11 @@ public: Setting pluginFiles{this, {}, "plugin-files", "Plugins to dynamically load at nix initialization time."}; + + Setting experimentalFeatures{this, {}, "experimental-features", + "Experimental Nix features to enable."}; + + void requireExperimentalFeature(const std::string & name); }; diff --git a/src/nix/main.cc b/src/nix/main.cc index a80fd0ea6..22f5e8c4c 100644 --- a/src/nix/main.cc +++ b/src/nix/main.cc @@ -138,6 +138,8 @@ void mainWrapped(int argc, char * * argv) args.parseCmdline(argvToStrings(argc, argv)); + settings.requireExperimentalFeature("nix-command"); + initPlugins(); if (!args.command) args.showHelpAndExit(); diff --git a/tests/init.sh b/tests/init.sh index 19a12c1e2..6a119aad0 100644 --- a/tests/init.sh +++ b/tests/init.sh @@ -17,6 +17,7 @@ cat > "$NIX_CONF_DIR"/nix.conf <