Per https://github.com/jenkinsci/job-dsl-plugin/wiki/Migration#migrating-to-170, and warnings in the console on seed jobs, concurrentBuild() is deprecated for pipeline jobs. Is this is error? concurrent builds can certainly be enabled/disabled on pipeline jobs.
|Field||Original Value||New Value|
|Status||Open [ 1 ]||Fixed but Unreleased [ 10203 ]|
|Resolution||Fixed [ 1 ]|
|Released As||Job DSL 1.71|
|Status||Fixed but Unreleased [ 10203 ]||Closed [ 6 ]|