From 39a783ffff65769d4ee9ec83f22cca1838e4bd9a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Thu, 1 Dec 2022 16:59:18 +0100
Subject: [PATCH] Require flakes for the -I flake:... feature

---
 src/libcmd/common-eval-args.cc | 1 +
 src/libexpr/flake/flake.cc     | 2 ++
 src/libexpr/parser.y           | 1 +
 3 files changed, 4 insertions(+)

diff --git a/src/libcmd/common-eval-args.cc b/src/libcmd/common-eval-args.cc
index 237b7a4d2..9b4011e8a 100644
--- a/src/libcmd/common-eval-args.cc
+++ b/src/libcmd/common-eval-args.cc
@@ -161,6 +161,7 @@ SourcePath lookupFileArg(EvalState & state, std::string_view s)
     }
 
     else if (hasPrefix(s, "flake:")) {
+        settings.requireExperimentalFeature(Xp::Flakes);
         auto flakeRef = parseFlakeRef(std::string(s.substr(6)), {}, true, false);
         auto [accessor, _] = flakeRef.resolve(state.store).lazyFetch(state.store);
         return accessor->root();
diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index 05fd301e1..7c2278936 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -698,6 +698,8 @@ void callFlake(EvalState & state,
     const LockedFlake & lockedFlake,
     Value & vRes)
 {
+    settings.requireExperimentalFeature(Xp::Flakes);
+
     auto [lockFileStr, keyMap] = lockedFlake.lockFile.to_string();
 
     auto overrides = state.buildBindings(lockedFlake.nodePaths.size());
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index d395a2220..3fdde0e36 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -805,6 +805,7 @@ std::optional<SourcePath> EvalState::resolveSearchPathElem(const SearchPathElem
     }
 
     else if (hasPrefix(elem.second, "flake:")) {
+        settings.requireExperimentalFeature(Xp::Flakes);
         auto flakeRef = parseFlakeRef(elem.second.substr(6), {}, true, false);
         debug("fetching flake search path element '%s''", elem.second);
         auto [accessor, _] = flakeRef.resolve(store).lazyFetch(store);