Accept duplicates in env if they map to the same value. Fixes #607

src/debugpy/launcher/handlers.py

@@ -85,10 +85,16 @@ def property_or_debug_option(prop_name, flag_name):
  # overwrite the global env vars correctly. If debug config has entries that
  # differ in case only, that's an error.
  env = {k.upper(): v for k, v in os.environ.items()}
- n = len(env_changes)
- env_changes = {k.upper(): v for k, v in env_changes.items()}
- if len(env_changes) != n:
- raise request.isnt_valid('Duplicate entries in "env"')
+ new_env_changes = {}
+ for k, v in env_changes.items():
+ k_upper = k.upper()
+ if k_upper in new_env_changes:
+ if new_env_changes[k_upper] == v:
+ continue
+ else:
+ raise request.isnt_valid('Found duplicate in "env": {0}.'.format(k_upper))
+ new_env_changes[k_upper] = v
+ env_changes = new_env_changes
  if "DEBUGPY_TEST" in env:
  # If we're running as part of a debugpy test, make sure that codecov is not
  # applied to the debuggee, since it will conflict with pydevd.