actions: try disabling parallelism and switch back to stable

.github/actions/nix-ros-build-action/dist/index.js

@@ -1226,7 +1226,7 @@ class PackageSet {
                 this.failedPackages.set(drvPath, attr);
                 core.debug(`${attr} (${drvPath}) failed to build`);
                 // Get last 10 lines of stderr
-                const message = e.stderr.split('\n').slice(-100).join("\n");
+                const message = e.stderr.split('\n').slice(-30).join("\n");
                 return {
                     status: 5 /* BUILD_FAILURE */,
                     attr, drvPath, message

.github/actions/nix-ros-build-action/src/main.ts

@@ -120,7 +120,7 @@ class PackageSet {
       this.failedPackages.set(drvPath, attr)
       core.debug(`${attr} (${drvPath}) failed to build`)
       // Get last 10 lines of stderr
-      const message = e.stderr.split('\n').slice(-100).join("\n")
+      const message = e.stderr.split('\n').slice(-30).join("\n")
       return {
         status: BuildStatus.BUILD_FAILURE,
         attr, drvPath, message

.github/workflows/build.yaml

@@ -21,10 +21,8 @@ jobs:
     - uses: actions/checkout@v2
     - uses: cachix/install-nix-action@v13
       with:
-        # Use Nix unstable to fix https://github.com/NixOS/nix/issues/1216
-        install_url: https://nixos-nix-install-tests.cachix.org/serve/cvzc8mz8jp1k2iaqq5x8kvx6rh8yh3qz/install
-        install_options: --tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve
         extra_nix_config: |
+          max-jobs = 1
           extra-platforms = aarch64-linux
     - uses: docker/setup-qemu-action@v1
     - uses: cachix/cachix-action@v9