Do not install dependencies that are built-in libraries

platformio/commands/lib/helpers.py

@@ -14,6 +14,7 @@
 
 import os
 
+from platformio import util
 from platformio.compat import ci_strings_are_equal
 from platformio.package.manager.platform import PlatformPackageManager
 from platformio.package.meta import PackageSpec
@@ -22,6 +23,7 @@ from platformio.project.config import ProjectConfig
 from platformio.project.exception import InvalidProjectConfError
 
 
+@util.memoized(expire="60s")
 def get_builtin_libs(storage_names=None):
     # pylint: disable=import-outside-toplevel
     from platformio.package.manager.library import LibraryPackageManager
@@ -45,8 +47,8 @@ def get_builtin_libs(storage_names=None):
     return items
 
 
-def is_builtin_lib(name, storages=None):
-    for storage in storages or get_builtin_libs():
+def is_builtin_lib(name):
+    for storage in get_builtin_libs():
         for lib in storage["items"]:
             if lib.get("name") == name:
                 return True

platformio/package/manager/library.py

@@ -15,6 +15,7 @@
 import json
 import os
 
+from platformio.commands.lib.helpers import is_builtin_lib
 from platformio.package.exception import MissingPackageManifestError
 from platformio.package.manager.base import BasePackageManager
 from platformio.package.meta import PackageSpec, PackageType
@@ -77,3 +78,13 @@ class LibraryPackageManager(BasePackageManager):  # pylint: disable=too-many-anc
                 if fname.endswith((".c", ".cpp", ".h", ".hpp", ".S")):
                     return root
         return path
+
+    def install_dependency(self, dependency):
+        spec = self.dependency_to_spec(dependency)
+        # skip built-in dependencies
+        not_builtin_conds = [spec.external, spec.owner]
+        if not any(not_builtin_conds):
+            not_builtin_conds.append(not is_builtin_lib(spec.name))
+        if any(not_builtin_conds):
+            return super(LibraryPackageManager, self).install_dependency(dependency)
+        return None