build.py: uh slightly better depency stuff

build.py

@@ -69,18 +69,29 @@ def fetch_manifest(pkgname, pkgver=None):
 def rebuild_package(packages, repo_dir=None):
     if isinstance(packages, str):
         packages = [packages]
+
+    db = load_db()  # <-- load db once
+
     for pkg in packages:
+        if pkg not in db["installed"]:
+            print(f"[fempkg] Skipping rebuild of {pkg}: not installed.")
+            continue
+
         print(f"[fempkg] Rebuilding dependency: {pkg}")
+
         dep_recipe = None
         if repo_dir:
             dep_recipe = os.path.join(repo_dir, f"{pkg}.recipe.py")
             if not os.path.exists(dep_recipe):
                 print(f"Warning: recipe for {pkg} not found in {repo_dir}.")
                 dep_recipe = None
+
         if not dep_recipe:
             dep_recipe = fetch_recipe(pkg)
+
         build_package(dep_recipe, repo_dir, force_rebuild=True)
 
+
 def extract_tar_zst_with_progress(tar_path, dest="/"):
     """
     Extract a .tar.zst archive with a progress bar.