feat(cli): add bind mount support for manifest in chroot

When using the manifest command with --root, bind mount the current working
directory to /usm-wd inside the chroot environment. This allows the manifest
command to access the original working directory files while running in the
chroot context.

src/cli/Cli.vala

@@ -21,21 +21,37 @@ public static int main(string[] args) {
                 printerr("Expected path after --root\n");
                 return 255;
             }
+
+            
+            if(command == "manifest") {
+                var wd = File.new_build_filename(root_path, "usm-wd");
+                if(!wd.query_exists()) {
+                    wd.make_directory();
+                }
+                Linux.umount(wd.get_path());
+                var res = Linux.mount(Environment.get_current_dir(), wd.get_path(), "", Linux.MountFlags.BIND);
+                if(res != 0) {
+                    printerr(@"Unable to bind mount working directory\n");
+                }
+            }
+
             var result = Posix.chroot(root_path);
             if(result != 0) {
                 printerr(@"Unable to chroot to \"$root_path\": $(Posix.strerror(result))\n");
                 return result;
             }
+
+            if(command == "manifest") {
+                Environment.set_current_dir("/usm-wd");
+            }
     
-            arguments.remove_at(root_flag_pos);
-            arguments.remove_at(root_flag_pos+1);
+            arguments.remove("--root");
+            arguments.remove(root_path);
         }
     
         if(command == "manifest") {
-            var m_args = new Invercargill.DataStructures.Vector<string>();
-            m_args.add_all(Invercargill.Wrap.array(args));
-            m_args.remove("manifest");
-            return manifest_main(m_args.to_array());
+            arguments.remove("manifest");
+            return manifest_main(arguments.to_array());
         }
         if(command == "info") {
             return info(args);

src/cli/meson.build

@@ -7,5 +7,6 @@ sources += files('Scaffold.vala')
 
  deps = dependencies
  deps += usm_dep
+ deps += meson.get_compiler('vala').find_library('linux')
 
 executable('usm', sources, dependencies: deps, install: true)