For overridden plugins currently, namely configuration-as-code and essentials, they will be downloaded and put on the disk with their remote names.
To illustrate, short version:
[...] and saving to /evergreen/jenkins/home/plugins/configuration-as-code-0.9-alpha-rc292.ee88abe834b2.hpi [...] and saving to /evergreen/jenkins/home/plugins/essentials-0.3-rc20.a3f76cdd1348.hpi
Fuller logs:
cat container-logs | egrep '(essentials)|(configuration-as-code)' info: Watching /evergreen/jenkins/var/logs/essentials.log.0 info: Fetching http://repo.jenkins-ci.org/incrementals/io/jenkins/configuration-as-code/0.9-alpha-rc292.ee88abe834b2/configuration-as-code-0.9-alpha-rc292.ee88abe834b2.hpi info: Fetching http://repo.jenkins-ci.org/incrementals/io/jenkins/configuration-as-code/0.9-alpha-rc292.ee88abe834b2/configuration-as-code-0.9-alpha-rc292.ee88abe834b2.hpi and saving to /evergreen/jenkins/home/plugins/configuration-as-code-0.9-alpha-rc292.ee88abe834b2.hpi info: Fetching http://repo.jenkins-ci.org/incrementals/io/jenkins/plugins/essentials/0.3-rc20.a3f76cdd1348/essentials-0.3-rc20.a3f76cdd1348.hpi info: Fetching http://repo.jenkins-ci.org/incrementals/io/jenkins/plugins/essentials/0.3-rc20.a3f76cdd1348/essentials-0.3-rc20.a3f76cdd1348.hpi and saving to /evergreen/jenkins/home/plugins/essentials-0.3-rc20.a3f76cdd1348.hpi info: Download complete /evergreen/jenkins/home/plugins/essentials-0.3-rc20.a3f76cdd1348.hpi info: Download complete /evergreen/jenkins/home/plugins/configuration-as-code-0.9-alpha-rc292.ee88abe834b2.hpi