Fixed FileNotFoundErrors with the files in store (#707)

* boot the scaffold before/during the topology, so file deps are available

* Fallback mtimes for missing files

bsb/config/_config.py

@@ -78,6 +78,9 @@ def default(cls, **kwargs):
         return conf
 
     def _bootstrap(self, scaffold):
+        # Activate the scaffold property of each config node
+        _boot_nodes(self, scaffold)
+        self._config_isbooted = True
         # Initialise the topology from the defined regions
         regions = builtins.list(self.regions.values())
         # Arrange the topology based on network boundaries
@@ -92,9 +95,6 @@ def _bootstrap(self, scaffold):
                 "__unmanaged__", RegionGroup(children=builtins.list(unmanaged))
             )
             topology.children.append(r)
-        # Activate the scaffold property of each config node
-        _boot_nodes(self, scaffold)
-        self._config_isbooted = True
 
     def _update_storage_node(self, storage):
         if self.storage.engine != storage.format:

bsb/storage/_files.py

@@ -165,7 +165,15 @@ def find(self, file: FileDependency):
     @_abc.abstractmethod
     def should_update(self, file: FileDependency, stored_file):
         path = _uri_to_path(file.uri)
-        return _os.path.getmtime(path) > stored_file.mtime
+        try:
+            file_mtime = _os.path.getmtime(path)
+        except FileNotFoundError:
+            return False
+        try:
+            stored_mtime = stored_file.mtime
+        except Exception:
+            return True
+        return file_mtime > stored_mtime
 
     @_abc.abstractmethod
     def get_content(self, file: FileDependency):