It's not possible to override ENV var from config/cucumber.yml

[bayandin]

If in config/cucumber.yml for any project env var is specified it is impossible to override it from CLI.

For example

# in config/cucumber.yml:
some_profile: SOME_VAR=1

$ parallel_cucumber --debug --cucumber-options ' SOME_VAR=2 -p some_profile' features/functional/some.feature
...
== Running command `cucumber ... SOME_VAR=2 ... SOME_VAR=1 features/functional/some.feature ...`
...

It seems there is a problem in batch_mapped_files function — it should handle duplicated ENV vars (and replace old ones cucumber config with new ones from CLI/--cucumber-options).