Don't require the top-level flake to be lockable

Even with lazy trees, this forced a NAR hash computation for path
flakes that we don't want.

Author: edolstra

src/libflake/flake.cc

@@ -436,7 +436,7 @@ lockFlake(const Settings & settings, EvalState & state, const FlakeRef & topRef,
     auto useRegistriesTop = useRegistries ? fetchers::UseRegistries::All : fetchers::UseRegistries::No;
     auto useRegistriesInputs = useRegistries ? fetchers::UseRegistries::Limited : fetchers::UseRegistries::No;
 
-    auto flake = getFlake(state, topRef, useRegistriesTop, {}, lockFlags.requireLockable);
+    auto flake = getFlake(state, topRef, useRegistriesTop, {}, false);
 
     if (lockFlags.applyNixConfig) {
         flake.config.apply(settings);

tests/functional/nix-profile.sh

@@ -54,7 +54,7 @@ cp "${config_nix}" "$flake1Dir"/
 nix-env -f ./user-envs.nix -i foo-1.0
 nix profile list | grep -A2 'Name:.*foo' | grep 'Store paths:.*foo-1.0'
 nix profile add "$flake1Dir" -L
-nix profile list | grep -A4 'Name:.*flake1' | grep 'Locked flake URL:.*narHash'
+#nix profile list | grep -A4 'Name:.*flake1' | grep 'Locked flake URL:.*narHash'
 [[ $("$TEST_HOME"/.nix-profile/bin/hello) = "Hello World" ]]
 [ -e "$TEST_HOME"/.nix-profile/share/man ]
 # shellcheck disable=SC2235