Fix wrongly identified circular dependencies

src/buildstream/_loader/loader.py

@@ -128,6 +128,15 @@ def load(self, targets):
 
         for target in targets:
             with PROFILER.profile(Topics.LOAD_PROJECT, target):
+
+                # As we are attempting to load a subproject element via the
+                # command line ensure fully loaded.
+                #
+                # Other callers of `_parse_name` or `_load_file` that reference
+                # files through a project element or otherwise do not need to
+                # ensure fully loaded.
+                self.project.ensure_fully_loaded()
+
                 _junction, name, loader = self._parse_name(target, None)
                 element = loader._load_file(name, None)
                 target_elements.append(element)
@@ -190,14 +199,6 @@ def get_loader(self, name, provenance_node, *, load_subprojects=True):
         junction_path = name.split(":")
         loader = self
 
-        #
-        # In this case we are attempting to load a subproject element via the
-        # command line instead of referencing the subproject through a project
-        # element or otherwise.
-        #
-        if provenance_node is None and load_subprojects:
-            self.project.ensure_fully_loaded()
-
         circular_provenance_node = self._loader_search_provenances.get(name, None)
         if circular_provenance_node and load_subprojects:
 
@@ -796,15 +797,12 @@ def provenance_str():
         # immediately and move on to the target.
         #
         if load_element.link_target:
-            _, filename, loader = self._parse_name(
-                load_element.link_target.as_str(), load_element.link_target, load_subprojects=load_subprojects
+            return self.get_loader(
+                load_element.link_target.as_str(),
+                load_element.link_target,
+                load_subprojects=load_subprojects,
             )
-            if not loader:
-                # `loader` should never be None if `load_subprojects` is True
-                assert not load_subprojects
-                return None
 
-            return loader.get_loader(filename, load_element.link_target, load_subprojects=load_subprojects)
 
         # If we're only performing a lookup, we're done here.
         #

tests/format/junctions.py

@@ -593,10 +593,17 @@ def test_override_twice(cli, tmpdir, datafiles):
 @pytest.mark.parametrize(
     "target,expected_result",
     [
-        ("target.bst", "pony"),
-        ("self-junction.bst:target.bst", "horsy"),
+        ("subproject.bst:target.bst", "pony"),
+        ("subproject.bst:self-junction.bst:target.bst", "horsy"),
+        ("link.bst", "pony"),
+        ("nested-link.bst", "horsy"),
+    ],
+    ids=[
+        "direct-target",
+        "override-target",
+        "link-target",
+        "link-override-target",
     ],
-    ids=["direct-target", "override-target"],
 )
 def test_override_self(cli, datafiles, target, expected_result):
     project = os.path.join(str(datafiles), "override-self")
@@ -922,7 +929,7 @@ def test_include_vars_optional(cli, datafiles, use_species, expected_result):
 @pytest.mark.datafiles(DATA_DIR)
 @pytest.mark.parametrize(
     "target",
-    ["target.bst", "subproject.bst:target.bst"],
+    ["target.bst", "subproject.bst:target.bst", "intermediate-project.bst:subproject.bst:target.bst"],
     ids=["toplevel-target", "subproject-target"],
 )
 @pytest.mark.parametrize(

tests/format/junctions/include-complex/alternative-placeholder.bst

@@ -0,0 +1 @@
+kind: stack

tests/format/junctions/include-complex/intermediate-project.bst

@@ -0,0 +1,12 @@
+kind: junction
+
+sources:
+- kind: local
+  path: intermediate-project
+
+config:
+  overrides:
+    subproject.bst:placeholder.bst: alternative-placeholder.bst
+
+  options:
+    animal: '%{animal}'

tests/format/junctions/include-complex/intermediate-project/project.conf

@@ -0,0 +1,15 @@
+name: intermediate-project
+min-version: 2.0
+
+(@):
+- subproject.bst:include.yml
+
+options:
+  animal:
+    type: enum
+    description: the animal
+    values:
+    - pony
+    - horsy
+    default: pony
+    variable: animal

tests/format/junctions/include-complex/intermediate-project/subproject.bst

@@ -0,0 +1,9 @@
+kind: junction
+sources:
+- kind: local
+  path: subproject
+
+config:
+
+  options:
+    target_animal: '%{animal}'

tests/format/junctions/include-complex/intermediate-project/subproject/placeholder.bst

@@ -0,0 +1 @@
+kind: stack

tests/format/junctions/include-complex/subproject/project.conf → tests/format/junctions/include-complex/intermediate-project/subproject/project.conf

@@ -9,3 +9,4 @@ options:
     - pony
     - horsy
     default: pony
+    variable: target_animal

tests/format/junctions/include-complex/subproject.bst

@@ -1,8 +1,4 @@
-kind: junction
-sources:
-- kind: local
-  path: subproject
+kind: link
 
 config:
-  options:
-    target_animal: '%{animal}'
+  target: intermediate-project.bst:subproject.bst

tests/format/junctions/override-self/link.bst

@@ -0,0 +1,4 @@
+kind: link
+
+config:
+  target: subproject.bst:target.bst

tests/format/junctions/override-self/nested-link.bst

@@ -0,0 +1,4 @@
+kind: link
+
+config:
+  target: subproject.bst:self-junction.bst:target.bst

tests/format/junctions/override-self/project.conf

@@ -1,6 +1,6 @@
 name: test
 min-version: 2.0
 
-junctions:
-  internal:
-  - self-junction.bst
+
+(@):
+- subproject.bst:self-junction.bst:include.yml

tests/format/junctions/override-self/subproject.bst

@@ -0,0 +1,4 @@
+kind: junction
+sources:
+- kind: local
+  path: subproject

tests/format/junctions/override-self/subproject/project.conf

@@ -0,0 +1,9 @@
+name: subproject
+min-version: 2.0
+
+junctions:
+  internal:
+  - self-junction.bst
+
+# (@):
+# - self-junction.bst:include.yml

tests/format/junctions/override-self/self-junction.bst → tests/format/junctions/override-self/subproject/self-junction.bst

@@ -3,6 +3,7 @@ sources:
 - kind: local
   path: .
 
+
 config:
   overrides:
     target.bst: alternative.bst