From Aaron Hallberg blog:
[…] change in TFS Build SP1 which reduced build log noise by cutting out the build steps for project-to-project references […] the fix in SP1 didn’t actually fix the problem, at least not completely.
[…] As such, if a project was referenced by 10 other projects the fix in SP1 would reduce the number of spurious build steps from 10*3 to 9*3 rather than removing them altogether.
A hotfix is finally available that will address the remaining parts of the problem […]
VSTS MVP colleague Mathias Olausson reports:
“before SP1 the build time was about 2h 30 min, with SP1 build time in average 65 minutes and with the build hotfix we’re now down to less than 40 minutes. The build log has changed from 5500 lines down to 550.”
Download hotfix: TFSBuild TargetsNotLogged property fails to cut down noisy builds
Additional Info: KB article 958845