The Xcode Integration Plugin has the function of importing the secret key and certificate of the developer account into the temporary key chain, but as the constraint of macOS can not handle different key chain for each session, the job handling the key chain If you execute them in parallel, this will not work properly.
As one of workarounds, it is impossible to limit the maximum number of jobs around Jenkins' node to 1 and to execute multiple nodes with different macOS accounts.
Setting up a build step
Add the XCode build step to a free-style project and set the target (e.g.
MyApp), configuration (e.g.
Release) and check the build IPA and update version number options. This will give you a single, versioned .ipa file. You can also select to clean the project before a build; while this will make sure that the project is starting from a clean state, it will make large projects take a lot longer.