gng-build-agent: Move startup code into lua module "startup"

gng-build-agent/lua/startup.lua

@@ -0,0 +1,33 @@
+local startup = {}
+
+function startup.init(pkg_definition)
+    print("Init called with \"" .. pkg_definition .. "\"...")
+    pkg_defaults = {
+        bootstrap = false,
+
+        build_dependencies = {},
+        check_dependencies = {},
+
+        prepare = function() end,
+        build = function() end,
+        check = function() end,
+        install = function() end,
+        polish = function() end,
+    }
+
+    PKG_func, err = loadfile(pkg_definition)
+
+    if PKG_func == nil then
+        error("Failed to load \"" .. pkg_definition .. "\" in gng-build-agent: "..err)
+    end
+
+    _G.PKG = PKG_func()
+
+    for k, v in pairs(pkg_defaults) do
+        if PKG[k] == nil then
+            PKG[k] = v
+        end
+    end
+end
+
+return startup

gng-build-agent/src/engine.rs

@@ -168,35 +168,7 @@ impl EngineBuilder {
         engine.load_functions()?;
 
         let script = format!(
-            r#"
-package.path = "/gng/lua/?.lua"
-
-pkg_defaults = {{
-   bootstrap = false,
-
-   build_dependencies = {{}},
-   check_dependencies = {{}},
-
-   prepare = function() end,
-   build = function() end,
-   check = function() end,
-   install = function() end,
-   polish = function() end,
-}}
-
-PKG_func, err = loadfile("{}")
-
-if PKG_func == nil then
-    error("Failed to load /gng/build.lua in gng-build-agent: "..err)
-end
-
-PKG = PKG_func()
-
-for k, v in pairs(pkg_defaults) do
-    if PKG[k] == nil then
-        PKG[k] = v
-    end
-end"#,
+            "package.path = \"/gng/lua/?.lua\"\nrequire(\"startup\").init(\"{}\")",
             build_file.to_string_lossy().as_ref()
         );