Lambda environment configuration fails when using 'GString' for value

[DALDEI]

lambda { 
   environment = [
      KEY:  "value/${with}/replacement"
  ] 
}

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':migrateSessionFunction'.
> Unable to marshall request to JSON: Unable to marshall request to JSON: org.codehaus.groovy.runtime.GStringImpl cannot be cast to java.lang.String

Succeeds:

lambda { 
     def String value = "value/${with}/replacement"
   environment = [ 
      KEY:  value
  ] 
}