We have several projects in CruiseControl and I noticed that often 2 or more projects are building at the same time. This seems to be causing conflicts. Often, a build fails and if I look at the reason, it's failing to access some file, and if I wait until the other build completes, I can just force-build the failed build and it will succeed.
How can I configure CC so that it won't run builds concurrently if they are going to conflict with each other?
You have to do all builds that depend on each other, in one queue.
The cruise control project configuration element has two attributes to control concurrency and order of build:
<project name="Project 1" queue="Q1" queuePriority="1">
With queue you can define in which queue the project shall be build, with queuePriority you can define the order of builds when several builds are requested.
So two projects that cannot be build in parallel have to be on the same queue, say queue="Q1". When the second projects is dependend on the first one, the second project must have a higher priority than the first.
You can use the Locking feature to define queus that should not run at the same time.
This is available in version 1.4.3
A sample from the documentation:
<cruisecontrol>
<queue name="Q1" lockqueues="Q2"/>
<queue name="Q2" lockqueues="Q1"/>
<project name="MyFirstProject" queue="Q1" queuePriority="1">
...
</project>
...
<project name="MySecondProject" queue="Q2" queuePriority="1">
...
</project>
...
</cruisecontrol>