universe: go: improve cache management

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

pkg/universe.dagger.io/go/container.cue

@@ -18,25 +18,31 @@ import (
 	// Use go image
 	_image: #Image
 
-	_sourcePath: "/src"
-	_cachePath:  "/root/.cache/gocache"
+	_sourcePath:     "/src"
+	_modCachePath:   "/root/.cache/go-mod"
+	_buildCachePath: "/root/.cache/go-build"
 
 	docker.#Run & {
 		input:   *_image.output | docker.#Image
-		workdir: "/src"
-		command: name: "go"
+		workdir: _sourcePath
 		mounts: {
 			"source": {
 				dest:     _sourcePath
 				contents: source
 			}
-			"go assets cache": {
+			"go mod cache": {
 				contents: core.#CacheDir & {
-					id: "\(name)_assets"
+					id: "\(name)_mod"
 				}
-				dest: _cachePath
+				dest: _modCachePath
+			}
+			"go build cache": {
+				contents: core.#CacheDir & {
+					id: "\(name)_build"
+				}
+				dest: _buildCachePath
 			}
 		}
-		env: GOMODCACHE: _cachePath
+		env: GOMODCACHE: _modCachePath
 	}
 }