Allow specifying a library from the current project as a dependency.

SConscript

@@ -60,7 +60,7 @@ def _find_recipe(env: Environment, recipe_name: str):
             source_file = try_source_file
             break
     if not source_file:
-        raise Exception(f'Could not find recipe {recipe_name}.')
+        env.Error(f'Could not find recipe for {recipe_name}.')
     spec = importlib.util.spec_from_file_location(recipe_name, source_file)
     recipe = importlib.util.module_from_spec(spec)
     recipe.env = env
@@ -332,6 +332,14 @@ def _wrap_builder(builder, target_type: TargetType):
     def _wrapped(env, dependencies = {}, *args, **kwargs):
         target_dependencies = []
         for name, version_spec in dependencies.items():
+            if version_spec == {}:
+                dep_target = _find_target(env, name)
+                if dep_target is not None and dep_target.target_type == TargetType.LIBRARY:
+                    if 'LIBS' in kwargs:
+                        kwargs['LIBS'].append(dep_target)
+                    else:
+                        kwargs['LIBS'] = [dep_target]
+                    continue
             target_dependencies.append(_add_dependency(env, name, _parse_version_spec(version_spec)))
 
         if 'CPPPATH' not in kwargs:
@@ -360,7 +368,7 @@ def _wrap_builder(builder, target_type: TargetType):
         else:
             trgt = _target_entry(kwargs.get('target'))
             if trgt is not None:
-                target.name = str(_target_entry(kwargs['target']).name)
+                target.name = str(trgt.name)
             else:
                 target.name = 'Unknown target'
         target.target_type = target_type
@@ -451,6 +459,12 @@ def _finalize(env: Environment):
             dependency = dependency.target
         env.Depends(dependant, dependency)
 
+def _find_target(env: Environment, target_name: str) -> '_Target|None':
+    for target in env['SPP_TARGETS']:
+        if target.name == target_name:
+            return target
+    return None
+
 def _get_fallback_cache_dir() -> str:
     return Dir('#cache').abspath
 
@@ -893,6 +907,7 @@ env.AddMethod(_wrap_builder(env.UnityStaticLibrary, TargetType.LIBRARY), 'UnityS
 env.AddMethod(_wrap_builder(env.UnitySharedLibrary, TargetType.LIBRARY), 'UnitySharedLibrary')
 env.AddMethod(_module, 'Module')
 env.AddMethod(_finalize, 'Finalize')
+env.AddMethod(_find_target, 'FindTarget')
 
 if hasattr(env, 'Gch'):
     env.AddMethod(_wrap_builder(env.Gch), 'Gch')