Report progress when resolving elements

src/buildstream/_context.py

diff --git a/src/buildstream/_context.py b/src/buildstream/_context.py
index 8345ec1..1da80d4 100644
--- a/src/buildstream/_context.py
+++ b/src/buildstream/_context.py
@@ -565,6 +565,7 @@
             self._last_progress_length = 0
             progress = Progress(self, activity_name, total=total, unique_id=unique_id)
             yield progress
+            self._finish_progress()
 
     def report_progress(self, message_text, unique_id=None):
         new_len = len(message_text)
@@ -679,6 +680,10 @@
     def set_artifact_files_optional(self):
         self.require_artifact_files = False
 
+    def _finish_progress(self):
+        sys.stderr.write("\n")
+        sys.stderr.flush()
+
     # _record_message()
     #
     # Records the message if recording is enabled

src/buildstream/_progress.py

diff --git a/src/buildstream/_progress.py b/src/buildstream/_progress.py
index d762f73..82f6d40 100644
--- a/src/buildstream/_progress.py
+++ b/src/buildstream/_progress.py
@@ -35,6 +35,9 @@
             self._total += count
         self._check_report_progress()
 
+    def get_total(self):
+        return self._total
+
     def add_progress(self, count):
         self._count += count
         self._check_report_progress()

src/buildstream/_project.py

diff --git a/src/buildstream/_project.py b/src/buildstream/_project.py
index 3d5714f..1da8987 100644
--- a/src/buildstream/_project.py
+++ b/src/buildstream/_project.py
@@ -454,9 +454,13 @@
                                              ticker=None,
                                              fetch_subprojects=fetch_subprojects)
 
-        with self._context.timed_activity("Resolving elements"):
+            # meta_elements is a list of target meta elements in a tree structure,
+            # not a list of all elements.
+            total_elements = progress.get_total()
+
+        with self._context.progress_activity("Resolving elements", total=total_elements) as progress:
             elements = [
-                Element._new_from_meta(meta)
+                Element._new_from_meta(meta, progress)
                 for meta in meta_elements
             ]
 

src/buildstream/element.py

diff --git a/src/buildstream/element.py b/src/buildstream/element.py
index 08326c6..3d8d014 100644
--- a/src/buildstream/element.py
+++ b/src/buildstream/element.py
@@ -962,12 +962,13 @@
     #
     # Args:
     #    meta (MetaElement): The meta element
+    #    progress (Progress): An object to report progress to
     #
     # Returns:
     #    (Element): A newly created Element instance
     #
     @classmethod
-    def _new_from_meta(cls, meta):
+    def _new_from_meta(cls, meta, progress=None):
 
         if not meta.first_pass:
             meta.project.ensure_fully_loaded()
@@ -993,15 +994,18 @@
 
         # Instantiate dependencies
         for meta_dep in meta.dependencies:
-            dependency = Element._new_from_meta(meta_dep)
+            dependency = Element._new_from_meta(meta_dep, progress)
             element.__runtime_dependencies.append(dependency)
             dependency.__reverse_dependencies.add(element)
 
         for meta_dep in meta.build_dependencies:
-            dependency = Element._new_from_meta(meta_dep)
+            dependency = Element._new_from_meta(meta_dep, progress)
             element.__build_dependencies.append(dependency)
             dependency.__reverse_dependencies.add(element)
 
+        if progress:
+            progress.add_progress(1)
+
         return element
 
     # _clear_meta_elements_cache()