Executing the "Reload Configuration from Disk" while builds are running causes
information about those builds to be lost.
POSTing a new configuration to /job/JOBNAME/config.xml also causes the exact same problem. Yet editing job configuration interactively using the web form does not show the problem.
I had two builds running when I reloaded configuration to pick up manual changes
to one project (not running a build) config.xml file. When the browser
refreshed, the builds were still shown as actively building in the Build
Executor Status frame but the status indicators were no longer blinking and the
project pages did not show any builds running for those projects.
It appears that part of Hudson thought that the builds had been canceled because
they were queued, blocked by themselves. The original builds appeared to
finsish normally and then the queued builds ran. There was no record of the
original build that had been running when the config reloaded.
Note: If Jenkins is completely restarted, by shutting down and starting up the service, the missing build re-appears. (Of course, doing that each time is unacceptable, just trying to help focus the debugging.)