Given the following snippet of a Jenkinsfile:

environment {
PYTEST_ADDOPTS =
"-n=10 " +
"--color=yes " +
"--tb=short " +
"--driver=SauceLabs " +
"--variables=capabilities.json"
}

When trying to run the above, we get:

Actual Results:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
WorkflowScript: 19: Environment variable values must either be strings or function calls. @ line 19, column 5.
PYTEST_ADDOPTS =
^

The workaround is to do:

environment {
PYTEST_ADDOPTS = "-n=10 --color=yes --tb=short --driver=SauceLabs --variables=capabilities.json"
}