nix, ci: build with Crane

This removes our dependency on cargo2nix, which was causing us some
issues. Whereas cargo2nix creates one Nix derivation per crate, Crane
uses only two derivations:

1. Build dependencies only
2. Build the final binary

This means that during the second step, no caching can be done. For
instance, if we do a change in garage_model, we need to recompile all of
the Garage crates including those that do not depend on garage_model.
On the upside, this allows all of the Garage crates to be built at once
using cargo build logic, which is optimized for high parallelism and
better pipelining between all of the steps of the build. All in all,
this makes most builds faster than cargo2nix.

A few other changes have been made to the build scripts and CI:

- Unit tests are now run within a Nix derivation. In fact, we have
  different derivations to run the tests using LMDB and Sqlite as
  metadata db engines.

- For debug builds, most CI steps now run in parallel (with the notable
  exception of the smoke test that runs after the build, which is
  inevitable).

- We no longer pass the GIT_VERSION argument when building debug builds
  and running the tests. This means that dev binaries and test
  binaries don't know the exact version of Garage they are from. That
  shouldn't be an issue in most cases.

- The not-dynamic.sh scripts has been fixed to fail if the file does not
  exist.

1 files changed, 54 insertions, 62 deletions

diff --git a/flake.nix b/flake.nix
index b1cb7dbb..ccaeba29 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,88 +6,80 @@
   inputs.nixpkgs.url =
     "github:NixOS/nixpkgs/7c4869c47090dd7f9f1bdfb49a22aea026996815";
 
-  inputs.flake-compat.url = "github:nix-community/flake-compat";
-
-  inputs.cargo2nix = {
-    # As of 2022-10-18: two small patches over unstable branch, one for clippy and one to fix feature detection
-    #url = "github:Alexis211/cargo2nix/a7a61179b66054904ef6a195d8da736eaaa06c36";
-
-    # As of 2023-04-25:
-    # - my two patches were merged into unstable (one for clippy and one to "fix" feature detection)
-    # - rustc v1.66
-    # url = "github:cargo2nix/cargo2nix/8fb57a670f7993bfc24099c33eb9c5abb51f29a2";
-
-    # Mainline cargo2nix as of of 2025-01-12 (branch release-0.11.0)
-    url = "github:cargo2nix/cargo2nix/ae19a9e1f8f0880c088ea155ab66cee1fa001f59";
-
-    # Rust overlay as of 2025-01-12
-    inputs.rust-overlay.url =
-      "github:oxalica/rust-overlay/162ab0edc2936508470199b2e8e6c444a2535019";
+  # Rust overlay as of 2025-01-12
+  inputs.rust-overlay.url =
+  "github:oxalica/rust-overlay/162ab0edc2936508470199b2e8e6c444a2535019";
+  inputs.rust-overlay.inputs.nixpkgs.follows = "nixpkgs";
 
-    inputs.nixpkgs.follows = "nixpkgs";
-    inputs.flake-compat.follows = "flake-compat";
-  };
+  inputs.crane.url = "github:ipetkov/crane";
 
-  inputs.flake-utils.follows = "cargo2nix/flake-utils";
+  inputs.flake-compat.url = "github:nix-community/flake-compat";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
 
-  outputs = { self, nixpkgs, cargo2nix, flake-utils, ... }:
+  outputs = { self, nixpkgs, flake-utils, crane, rust-overlay, ... }:
     let
-      git_version = self.lastModifiedDate;
       compile = import ./nix/compile.nix;
     in
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
+        packageFor = target: release: (compile {
+          inherit system target nixpkgs crane rust-overlay release;
+        }).garage;
+        testWith = extraTestEnv: (compile {
+          inherit system nixpkgs crane rust-overlay extraTestEnv;
+          release = false;
+        }).garage-test;
       in
       {
-        packages =
-          let
-            packageFor = target: (compile {
-              inherit system git_version target;
-              pkgsSrc = nixpkgs;
-              cargo2nixOverlay = cargo2nix.overlays.default;
-              release = true;
-            }).workspace.garage { compileMode = "build"; };
-          in
-          {
-            # default = native release build
-            default = packageFor null;
-            # other = cross-compiled, statically-linked builds
-            amd64 = packageFor "x86_64-unknown-linux-musl";
-            i386 = packageFor "i686-unknown-linux-musl";
-            arm64 = packageFor "aarch64-unknown-linux-musl";
-            arm = packageFor "armv6l-unknown-linux-musl";
+        packages = {
+          # default = native release build
+          default = packageFor null true;
+
+          # <arch> = cross-compiled, statically-linked release builds
+          amd64 = packageFor "x86_64-unknown-linux-musl" true;
+          i386 = packageFor "i686-unknown-linux-musl" true;
+          arm64 = packageFor "aarch64-unknown-linux-musl" true;
+          arm = packageFor "armv6l-unknown-linux-musl" true;
+
+          # dev = native dev build
+          dev = packageFor null false;
+
+          # test = cargo test
+          tests = testWith {};
+          tests-lmdb = testWith {
+            GARAGE_TEST_INTEGRATION_DB_ENGINE = "lmdb";
+          };
+          tests-sqlite = testWith {
+            GARAGE_TEST_INTEGRATION_DB_ENGINE = "sqlite";
           };
+        };
 
         # ---- developpment shell, for making native builds only ----
         devShells =
           let
-            shellWithPackages = (packages: (compile {
-              inherit system git_version;
-              pkgsSrc = nixpkgs;
-              cargo2nixOverlay = cargo2nix.overlays.default;
-            }).workspaceShell { inherit packages; });
+            targets = compile {
+              inherit system nixpkgs crane rust-overlay;
+            };
           in
           {
-            default = shellWithPackages
-              (with pkgs; [
-                rustfmt
-                clang
-                mold
-              ]);
+            default = targets.devShell;
 
             # import the full shell using `nix develop .#full`
-            full = shellWithPackages (with pkgs; [
-              rustfmt
-              rust-analyzer
-              clang
-              mold
-              # ---- extra packages for dev tasks ----
-              cargo-audit
-              cargo-outdated
-              cargo-machete
-              nixpkgs-fmt
-            ]);
+            full = pkgs.mkShell {
+              buildInputs = with pkgs; [
+                targets.toolchain
+                protobuf
+                clang
+                mold
+                # ---- extra packages for dev tasks ----
+                rust-analyzer
+                cargo-audit
+                cargo-outdated
+                cargo-machete
+                nixpkgs-fmt
+              ];
+            };
           };
       });
 }