Reading https://issues.jenkins-ci.org/browse/JENKINS-44598, this may be
due to re-using the same workspace and accumulating state there,
combined with possibly bugs in the git plugin itself. (Note this is
different from the workspace in which builds happen; this one lives on
the master and is just used for fetching).
We're hitting an issue in rpm-ostree where Jenkins'
git mergeis failing because of unmerged files:https://github.com/coreos/rpm-ostree/pull/2206
Reading https://issues.jenkins-ci.org/browse/JENKINS-44598, this may be due to re-using the same workspace and accumulating state there, combined with possibly bugs in the git plugin itself. (Note this is different from the workspace in which builds happen; this one lives on the master and is just used for fetching).
Let's just always nuke the workspace.