In Buildbot, pending runs are ones that haven't started yet. It's quite misleading if dashboard reports pending and current run as "pending". I don't think that we need a number for pending runs. Generally, Buildbot just coalesces all revisions, testing the most current one. So the number just means "how many incoming requests came during the current run". Some bots could be configured to not coalesce, or even to backtrack when idle. I'm not sure of all the details.
I think that there are two use cases for pending build indication: 1. It helps to know whether a fix for current problems has already landed. Currently, I have to go to either my webkit-changes folder in Mail, or to trac.webkit.org. This is tracked as bug 122180. 2. Sometimes bots get stuck, and looking at pending builds helps discover that. I think that this we should display ETA and last finish time for each bot (see also bug 122661). It's slightly non-trivial because there are sometimes multiple bots per tester, but not hard - the information is all available in JSON status. One way or another, the current situation with displaying pending build count is very confusing, especially so for testers, which will combine all pending runs for the next cycle.
<rdar://problem/15519672>
Created attachment 220023 [details] proposed patch
Created attachment 220026 [details] screenshot
Created attachment 220027 [details] with minor fixes Fixed an error caused by a last minute rename, and clamped pending revision count t be non-negative (it could theoretically become negative if trac was down or slow to respond).
Committed <http://trac.webkit.org/r161090>.