A pipe line with the followin g scm checkout configured:

     checkout ([poll: false,
                scm: [$class: 'GitSCM',
                      branches: [[name: '$GERRIT_BRANCH']],
                      doGenerateSubmoduleConfigurations: false,
                      extensions: [[$class: 'WipeWorkspace'],
                                   [$class: 'BuildChooserSetting',
                                            buildChooser: [$class: 'GerritTriggerBuildChooser']],
                                   [$class: 'UserIdentity',
                                             email: 'jenkins@xxxxx.xxxx.xxxx',
                                             name: 'Jenkins (NICOS release job)']
                                  ],
                       gitTool: 'Default',
                       submoduleCfg: [],
                       userRemoteConfigs: [[credentialsId: 'XXXX',
                                            refspec: '$GERRIT_REFSPEC',
                                            url: 'ssh://<host>$GERRIT_PROJECT']]
                     ]
                ])
 

does not configure user/email in the check-out repo.

From the build log:
[Pipeline] checkoutWiping out workspace first.
Cloning the remote Git repository
Cloning repository ssh://<......>
> /usr/bin/git init /home/jenkins/jobs/XXXXXXX/workspace # timeout=10
Fetching upstream changes from ssh://<.....>
> /usr/bin/git --version # timeout=10
using GIT_SSH to set credentials XXXXXXXXXXX
> /usr/bin/git fetch --tags --progress ssh://<.....> +refs/heads/:refs/remotes/origin/
> /usr/bin/git config remote.origin.url ssh://<.....> # timeout=10
> /usr/bin/git config --add remote.origin.fetch +refs/heads/:refs/remotes/origin/ # timeout=10
> /usr/bin/git config remote.origin.url ssh://<.....> # timeout=10
Fetching upstream changes from ssh://<.....>using GIT_SSH to set credentials 192.168.56.101
> /usr/bin/git fetch --tags --progress ssh://<.....> refs/heads/release-3.0
> /usr/bin/git rev-parse FETCH_HEAD^{commit} # timeout=10
Checking out Revision eb56ef5e23cebf5ba496421b32fcd650c503402d ($GERRIT_BRANCH)
Commit message: "simulation: do not emit warning if quiet"
> /usr/bin/git config core.sparsecheckout # timeout=10
> /usr/bin/git checkout -f eb56ef5e23cebf5ba496421b32fcd650c503402d
> /usr/bin/git rev-parse FETCH_HEAD^{commit} # timeout=10
> /usr/bin/git rev-list cef586346270967a0435d76501053395197cf6a5 # timeout=10
....
fatal: empty ident name (for <jenkins@67b4ac9c6b46.(none)>) not allowed