We have a multibranch pipeline which after being triggered immediately splits into 6 stages for various linux and windows platforms. The sequence of each of the pipelines goes like this:
- Obtain branch source (checkout scm)
- Obtain platform specific thirdparties (p4sync)
- Obtain common thirdparties (p4sync)
The problem I am having is pinning the thirdparty syncs to the same changelist as the branch, because each instance of a sync can set the P4_CHANGELIST environment variable (which seems to be updated globally) to a different value, so unless I perform a single sync ahead of all the others just to get the changelist and store it, I have a race condition.
What I would like to do is be able to put this at the start of my script, before I enter the pipeline block:
Which would ensure I have a global reference to the changelist that triggered the build to use for pinning the subsequent thirdparty syncs, that isn't overridden by any subsequent uses of p4sync.
I see that PerforceScm has a property P4Ref revision. Can this be exposed in the manner I'd like?
My current workaround consists of either wrapping an initial checkout in a lock step so that I can set the global variable after a first sync has completed (this delays all other parallel stages by the time it takes to sync, which can be up to 10 minutes currently)
or by trying to use a lock on updating the variable immediately after a checkout scm, which still has a race condition.