Rails 8.0.1 .. can somebody help? Master key is set in env variables and is equal to value in config/master.key

Cannot deploy to render

#18 [build 6/6] RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
#18 0.923 Missing encryption key to decrypt file with. Ask your team for your master key and write it to /rails/config/master.key or put it in the ENV['RAILS_MASTER_KEY'].
#18 ERROR: process "/bin/sh -c SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile" did not complete successfully: exit code: 1
------
 > [build 6/6] RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile:
0.923 Missing encryption key to decrypt file with. Ask your team for your master key and write it to /rails/config/master.key or put it in the ENV['RAILS_MASTER_KEY'].
------
Dockerfile:49
--------------------
  47 |     
  48 |     # Precompiling assets for production without requiring secret RAILS_MASTER_KEY
  49 | >>> RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
  50 |     
  51 |     
--------------------
error: failed to solve: process "/bin/sh -c SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile" did not complete successfully: exit code: 1
error: exit status 1