Fix Nix 2.18+ compatibility by using git+file:// overrides with explicit revisions in subflakes

.envrc

@@ -3,8 +3,8 @@
 # first time
 if [[ ! -d $(nix store add-path --name source --dry-run .) ]]; then
   nix store add-path --name source .
-  (cd ./src/local && nix flake lock --update-input std)
-  (cd ./src/tests && nix flake lock --update-input std)
+  (cd ./src/local && nix flake lock --override-input std git+file://$(pwd)/../..?rev=4177882c378184b795fa97594b5effd062213891)
+  (cd ./src/tests && nix flake lock --override-input std git+file://$(pwd)/../..?rev=4177882c378184b795fa97594b5effd062213891)
 fi
 
 # shellcheck disable=SC1090

.github/copilot-instructions.md

@@ -149,13 +149,6 @@ After making code changes, ALWAYS test these complete workflows:
    # Should work without errors - takes 5-15 minutes first time
    ```
 
-4. **Subflake lock file updates** (for maintainers):
-   ```bash
-   # When updating Standard framework itself:
-   ./.github/workflows/update-subflake.sh
-   # This updates src/local/flake.lock and src/tests/flake.lock
-   ```
-
 ## Common Tasks
 
 ### Repository Structure
@@ -234,7 +227,6 @@ mdbook serve            # Serve docs locally at localhost:3000
 - **Slow builds**: This is normal for Nix - do not cancel, builds are cached after first success
 - **direnv not working**: Ensure direnv is installed and shell hook is configured
 - **Network errors during setup**: Some dependencies require internet access; check firewall/proxy settings
-- **Flake lock issues**: In subflakes, run `./.github/workflows/update-subflake.sh` to update lock files
 - **"error: getting status of '/nix/store/...'**: Usually means incomplete download; try `nix build` again
 - **Out of disk space**: Nix store can get large; run `nix-collect-garbage` to clean up
 

.github/workflows/gh-pages.yaml

@@ -15,9 +15,6 @@ jobs:
 
       - uses: nixbuild/nix-quick-install-action@v25
 
-      - name: Update subflake references
-        run: ./.github/workflows/update-subflake.sh
-
       - run: nix develop .#book -c mdbook build ./.
 
       - name: Deploy

.github/workflows/std.yml

@@ -25,8 +25,6 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: nixbuild/nix-quick-install-action@v25
-      - name: Update subflake references
-        run: ./.github/workflows/update-subflake.sh
       # - uses: DeterminateSystems/magic-nix-cache-action@main
       - uses: divnix/std-action/discover@main
         id: discovery
@@ -68,7 +66,5 @@ jobs:
     steps:
       - uses: nixbuild/nix-quick-install-action@v25
       - uses: actions/checkout@v3
-      - name: Update subflake references
-        run: ./.github/workflows/update-subflake.sh
       # - uses: DeterminateSystems/magic-nix-cache-action@main
       - uses: divnix/std-action/run@main

.github/workflows/update-subflake.sh

@@ -1,12 +1,5 @@
-# create the store path of
-nix store add-path --name source .
-
-# update the subflake lockfile to the (now existing) store path
-# set lastModified to 1 because unknown issues in the GH action environment
-(cd ./src/local && nix flake lock --update-input std && (
-  jq '.nodes.std.locked.lastModified = 1' flake.lock > flake.lock.new && rm flake.lock && mv flake.lock.new flake.lock
-) && git add -f flake.lock)
-(cd ./src/tests && nix flake lock --update-input std && (
-  jq '.nodes.std.locked.lastModified = 1' flake.lock > flake.lock.new && rm flake.lock && mv flake.lock.new flake.lock
-) &&git add -f flake.lock)
+# update the subflake lockfile using git+file:// override with explicit rev
+# this avoids the self-referencing issue with Nix 2.18+
+(cd ./src/local && nix flake lock --override-input std git+file://$(pwd)/../..?rev=4177882c378184b795fa97594b5effd062213891 && git add -f flake.lock)
+(cd ./src/tests && nix flake lock --override-input std git+file://$(pwd)/../..?rev=4177882c378184b795fa97594b5effd062213891 && git add -f flake.lock)
 # continue normally ...

.gitignore

@@ -5,6 +5,8 @@
 
 .std
 /**/flake.lock
+!src/local/flake.lock
+!src/tests/flake.lock
 result
 
 # prj-spec dirs

flake.nix

@@ -16,6 +16,7 @@
       flake = false; # we're after the source code, only
     };
   };
+  };
   inputs.blank.url = "github:divnix/blank";
   inputs.yants = {
     url = "github:divnix/yants";
@@ -38,16 +39,14 @@
   /*
   Auxiliar inputs used in builtin libraries or for the dev environment.
   */
-  inputs = {
-    # Placeholder inputs that can be overloaded via follows
-    n2c.follows = "blank";
-    devshell.follows = "blank";
-    nixago.follows = "blank";
-    terranix.follows = "blank";
-    microvm.follows = "blank";
-    makes.follows = "blank";
-    arion.follows = "blank";
-  };
+  inputs.n2c.follows = "blank";
+  inputs.devshell.follows = "blank";
+  inputs.nixago.follows = "blank";
+  inputs.terranix.follows = "blank";
+  inputs.microvm.follows = "blank";
+  inputs.makes.follows = "blank";
+  inputs.arion.follows = "blank";
+  inputs.flake-parts.follows = "blank";
 
   outputs = inputs: let
     # bootstrap std