Performance of GetBuildVersion task about nerdbank.gitversioning

[AArnott]

This is great feedback. Thanks. Yes, I can think of some ways we can improve this.

[AArnott]

I'm working on this now, but it would be very helpful if you could collect perf traces of your build so that I can be sure I'm making the changes that will speed up your build. Can you please use PerfView to collect those traces?
After downloading it:

1. click Collect-> Collect (it may restart to elevate, then repeat this step)
2. Check the 'Zip' option
3. Expand "Advanced Options"
4. Check the "No V3.X NGEN Symbols" option
5. Make sure Current Dir and Data File are set to where you want to place the trace file(s).
6. Prepare to kick off a build that will demonstrate the problem. Arrange for the build you're measuring to last 10-20 seconds (by picking which projects to build, or using an incremental build).
7. Click Start Collection, and immediately kick off your build.
8. When your build is done, stop collection in PerfView.
9. It could take 30 seconds or even minutes to wrap up its work. Then send me the .zip file it creates.

This will give a very clear and reliable picture of where the time in your build goes, and in particular, I can look at the GetBuildVersion task time to make sure that all the expensive operations get saved and reused across all projects in the future.

[azeno]

I've added two traces. The AffectedAllProjects was a solution build (not re-build) which touched all 38 projects. The AffectedFiveProjects was after I changed one line of code and did a build of the top-level project file.

http://we.tl/EC5EKmHNuE

[AArnott]

Thanks. I'm taking a look now.

[AArnott]

@azeno: can you please try this fix to see if it helps your build?

NuGet package source: https://ci.appveyor.com/nuget/nerdbank-gitversioning
Version to upgrade to: 1.1.56-rc-gcfa44ca7d1

If the perf doesn't seem satisfactory even with these changes, please supply a fresh PerfView ETL trace with this updated version so I can get a look at what remains to be fixed.

[azeno]

Works like a charm! Thank you!