Fix T51762: Unit test script_alembic_import is failing.

Implemented workaround for use with the legacy depsgraph.

tests/python/CMakeLists.txt

@@ -474,6 +474,7 @@ if(WITH_ALEMBIC)
 		--python ${CMAKE_CURRENT_LIST_DIR}/bl_alembic_import_test.py
 		--
 		--testdir "${TEST_SRC_DIR}/alembic"
+		--with-legacy-depsgraph=${WITH_LEGACY_DEPSGRAPH}
 		)
 
 	else()
@@ -487,6 +488,7 @@ if(WITH_ALEMBIC)
 		--python ${CMAKE_CURRENT_LIST_DIR}/bl_alembic_import_test.py
 		--
 		--testdir "${TEST_SRC_DIR}/alembic"
+		--with-legacy-depsgraph=${WITH_LEGACY_DEPSGRAPH}
 		)
 
 	endif()

tests/python/bl_alembic_import_test.py

@@ -129,6 +129,9 @@ class SimpleImportTest(AbstractAlembicTest):
         bpy.data.cache_files[fname].filepath = relpath.replace('1.abc', '2.abc')
         bpy.context.scene.update()
 
+        if args.with_legacy_depsgraph:
+            bpy.context.scene.frame_set(10)
+
         x, y, z = cube.matrix_world.to_euler('XYZ')
         self.assertAlmostEqual(x, math.pi / 2, places=5)
         self.assertAlmostEqual(y, 0)
@@ -213,6 +216,8 @@ def main():
 
     parser = argparse.ArgumentParser()
     parser.add_argument('--testdir', required=True, type=pathlib.Path)
+    parser.add_argument('--with-legacy-depsgraph', default=False,
+                        type=lambda v: v in {'ON', 'YES', 'TRUE'})
     args, remaining = parser.parse_known_args(argv)
 
     unittest.main(argv=remaining)