Build parameters being exported to env vars as lowercase

When passing build parameters to my build using the API as described in Inject environment variables with the CircleCI API - CircleCI I am seeing the name of the build parameter lowercased when it is exported as an environment variable i.e.

curl \
  --header "Content-Type: application/json" \
  --header "Circle-Token: $CIRCLE_TOKEN" \
  --data '{"build_parameters": {"PARAM1": "value1", "param2": 500}}' \
  --request POST \

will result in the env var param1 being exported in the build environment. This behaviour is new in the last 24 hours.

Can confirm that we are affected by this behavior since 12 hours as well.

An internal build of ours got submitted to Production environment (Testflight) because of this change! :warning:

Can confirm, we’re also affected

I would guess that this is directly linked to whatever work was done for the update mentioned in

Which was placed into production in the last 24 hours.

While this thread is likely to be seen by the support staff it would make sense to also raise a support ticket so that you know it has been logged.