Problem: gomod2nix don't use the same golang version as project (#853)

* Problem: gomod2nix don't use the same golang version as project

Solution:
- build updateScript in nix expression.
- add workflow to check gomod2nix.toml up to date.

* tweag -> nix-community

.github/workflows/build.yml

@@ -395,3 +395,32 @@ jobs:
             ❌  `/runsim` simulation test has failed 😅
             Can further check [here](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }})
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  gomod2nix:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - id: changed-files
+        uses: tj-actions/[email protected]
+        with:
+          files: |
+            go.mod
+            go.sum
+      - uses: cachix/install-nix-action@v15
+        if: steps.changed-files.outputs.any_changed == 'true'
+      - name: update gomod2nix
+        run: nix run .#update-gomod2nix
+        if: steps.changed-files.outputs.any_changed == 'true'
+      - name: check working directory is clean
+        id: changes
+        run: |
+          set +e
+          (git diff --no-ext-diff --exit-code)
+          echo ::set-output name=changed::$?
+      - uses: actions/upload-artifact@v2
+        if: steps.changes.outputs.changed == 1
+        with:
+          name: gomod2nix.toml
+          path: ./gomod2nix.toml
+      - if: steps.changes.outputs.changed == 1
+        run: echo "Working directory is dirty" && exit 1

default.nix

@@ -3,6 +3,8 @@
 , buildGoApplication
 , nix-gitignore
 , go_1_18
+, writeShellScript
+, gomod2nix
 , rocksdb ? null
 , network ? "mainnet"  # mainnet|testnet
 , rev ? "dirty"
@@ -76,6 +78,16 @@ buildGoApplication rec {
     find $instrumented/bin/ -type f 2>/dev/null | xargs -r remove-references-to -t ${go} || true
   '';
 
+  passthru = {
+    # update script use the same golang version as the project
+    updateScript =
+      let helper = gomod2nix.override { inherit go; };
+      in
+      writeShellScript "${pname}-updater" ''
+        exec ${helper}/bin/gomod2nix
+      '';
+  };
+
   meta = with lib; {
     description = "Official implementation of the Crypto.org blockchain protocol";
     homepage = "https://crypto.org/";

flake.nix

@@ -7,7 +7,7 @@
       flake = false;
     };
     gomod2nix = {
-      url = "github:yihuang/gomod2nix";
+      url = "github:nix-community/gomod2nix";
       inputs.nixpkgs.follows = "nixpkgs";
       inputs.utils.follows = "flake-utils";
     };
@@ -42,6 +42,10 @@
           apps = {
             chain-maind = mkApp packages.chain-maind;
             chain-maind-testnet = mkApp packages.chain-maind-testnet;
+            update-gomod2nix = {
+              type = "app";
+              program = "${packages.chain-maind.updateScript}";
+            };
           };
           defaultPackage = packages.chain-maind;
           defaultApp = apps.chain-maind;

integration_tests/shell.nix

@@ -3,7 +3,6 @@ pkgs.mkShell {
   buildInputs = with pkgs; [
     # build tools
     go_1_18
-    gomod2nix
     rocksdb
 
     # lint tools

nix/sources.json

@@ -3,12 +3,12 @@
         "branch": "master",
         "description": "Convert applications using Go modules to Nix expressions",
         "homepage": null,
-        "owner": "yihuang",
+        "owner": "nix-community",
         "repo": "gomod2nix",
-        "rev": "2be74ae9177c9c897c3924a984cf8e85159832ce",
-        "sha256": "1rzc0dw0kcav0034y39qrwmvj9w127raq0x5rscz97mwcyjz3sp5",
+        "rev": "cc75990c60d01d9eedcf32ff4bf0055dd49c3ea1",
+        "sha256": "1s9m70q2jsr75hynx7q4brgbf22n1lfw5hc45mc3x4r9g4m8qrdz",
         "type": "tarball",
-        "url": "https://github.com/yihuang/gomod2nix/archive/2be74ae9177c9c897c3924a984cf8e85159832ce.tar.gz",
+        "url": "https://github.com/nix-community/gomod2nix/archive/cc75990c60d01d9eedcf32ff4bf0055dd49c3ea1.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "ibc-rs": {