sptimer assembly cache problem when using (redeploy.bat)

[norvegec]

Precondition:

1. my.wsp is deployed as farm solution with -GacDeployment parameter. my.dll is in GAC.
2. New feature is added to my.wsp with feature receiver. Package version isn't incremented, neither does assembly/file versions.
3. When redeploy.bat is executed, uninstall-remove my.wsp worked fine, but add-install 'my.wsp' is exited with error in

The Execute method of job definition "SPSolutionDeploymentJobDefinition" threw an exception. 
Failed to create receiver object from assembly **ommited**
System.ArgumentNullException at System.Activator.CreateInstance(Type type, Boolean nonPublic)

Solution: If restart-service SPTimerV4 is called before installing new version of my.wsp then it is completed successfully.

[matthiaseinig]

Thanks for reporting. Sounds like SPTimerV4 is still holding the code of the old assembly in runtime preventing you to update the receiver. But in regards of reducing downtime during the deployment process I would not restart SPTimerV4 in general. What you can do is to add a pre-deployment custom target in the CustomTargets.ps1 that runs either for all or only that specific WSPs (use the ProcessSolution hook for that) and calls RestartService "SPTimerV4" (this is the SPSD function in order to get the logging).