Install a dev-platform with ALL declared packages using a new `--with-all-packages` option // Resolve #3345

platformio/managers/platform.py

@@ -74,6 +74,7 @@ class PlatformManager(BasePkgManager):
         with_packages=None,
         without_packages=None,
         skip_default_package=False,
+        with_all_packages=False,
         after_update=False,
         silent=False,
         force=False,
@@ -84,6 +85,9 @@ class PlatformManager(BasePkgManager):
         )
         p = PlatformFactory.newPlatform(platform_dir)
 
+        if with_all_packages:
+            with_packages = list(p.packages.keys())
+
         # don't cleanup packages or install them after update
         # we check packages for updates in def update()
         if after_update: