cargoxx-pkgs registry skeleton

Empty package registry for cargoxx. flake.nix walks recipes/<name>/versions/*.toml, exposes each (name, version) as packages.<system>.{<name>_<safe_ver>, <name>}, and builds via cargoxx.lib.${system}.buildCppPackage with pkgs.fetchgit. .gitea/workflows/validate-pr.yml validates schema, refetches and verifies source sha256, smoke-builds, pushes $out to the binary cache, and labels auto-merge once the PR author is in maintainers.txt. .gitea/workflows/auto-merge.yml merges via tea on the auto-merge label.
2026-05-17 19:39:11 +00:00
commit f8a041f5b7
6 changed files with 289 additions and 0 deletions
--- a/flake.nix
+++ b/flake.nix
@@ -0,0 +1,88 @@
+{
+  description = "cargoxx package registry";
+
+  inputs = {
+    nixpkgs.url     = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+
+    # During local development we point at the sibling cargoxx checkout
+    # via an absolute `git+file://` URL. Once the registry lives on Gitea
+    # this becomes a Gitea URL pinned to a specific cargoxx revision —
+    # that pin, alongside `lock.cargoxx_rev` in each recipe, is what
+    # makes registry derivations deterministic across consumers (see
+    # docs/library-reuse-and-publish.md in the cargoxx repo).
+    cargoxx.url = "git+file:///home/mozart/cargoxx";
+  };
+
+  outputs = { self, nixpkgs, flake-utils, cargoxx }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+
+        # version_safe: 1.2.3 → "1_2_3". The attr name `<pkg>_<safe>` is
+        # the canonical handle for a (name, version) pair; bare `<pkg>`
+        # aliases the highest-versioned entry.
+        sanitizeVersion = v:
+          builtins.replaceStrings ["." "-" "+"] ["_" "_" "_"] v;
+
+        # Read recipes/<name>/versions/<v>.toml → buildCppPackage'd drv.
+        mkPackage = recipeFile:
+          let r = builtins.fromTOML (builtins.readFile recipeFile);
+          in cargoxx.lib.${system}.buildCppPackage {
+               src = pkgs.fetchgit {
+                 inherit (r.source) url;
+                 rev    = r.source.commit;
+                 hash   = r.source.sha256;
+               };
+               name = "${r.name}-${r.version}";
+             };
+
+        # builtins.readDir → attrset of name → type ("regular"/"directory").
+        # Yields [{ name, type }] entries, filtering on a predicate.
+        dirEntries = path: predicate:
+          if builtins.pathExists path
+          then pkgs.lib.filterAttrs (n: t: predicate n t) (builtins.readDir path)
+          else {};
+
+        # All package directories under recipes/.
+        packageNames = builtins.attrNames
+          (dirEntries ./recipes (_: t: t == "directory"));
+
+        # For one package: enumerate its versions, returning an attrset
+        # { "<pkg>_<safe>" = <drv>; "<pkg>" = <highest-version drv>; }.
+        versionsFor = pkgName:
+          let
+            versionsDir = ./recipes + "/${pkgName}/versions";
+            files = builtins.attrNames
+              (dirEntries versionsDir (n: t:
+                t == "regular" && pkgs.lib.hasSuffix ".toml" n));
+            versions = map (f:
+              let
+                version = pkgs.lib.removeSuffix ".toml" f;
+                attr    = "${pkgName}_${sanitizeVersion version}";
+                drv     = mkPackage (versionsDir + "/${f}");
+              in { inherit version attr drv; }
+            ) files;
+            byVersion = pkgs.lib.listToAttrs
+              (map (v: { name = v.attr; value = v.drv; }) versions);
+            highest = pkgs.lib.last
+              (pkgs.lib.sort (a: b:
+                builtins.compareVersions a.version b.version < 0) versions);
+            latestAlias =
+              if versions == [] then {}
+              else { ${pkgName} = highest.drv; };
+          in byVersion // latestAlias;
+
+        packagesAttrs = pkgs.lib.foldl' (acc: n:
+          acc // (versionsFor n)) {} packageNames;
+      in {
+        packages = packagesAttrs;
+
+        # Bare `nix flake check` should pass with zero recipes.
+        checks = {
+          schema-ok = pkgs.runCommand "registry-schema-ok" {} ''
+            touch $out
+          '';
+        };
+      });
+}