We're intermittently getting this error when fetching source from TFS:
2017-03-23T23:49:31.0591599Z ##[section]Starting: Build solution [SOLUTION-NAME].sln
2017-03-23T23:49:31.0591599Z ==============================================================================
2017-03-23T23:49:31.0591599Z Task : Visual Studio Build
2017-03-23T23:49:31.0591599Z Description : Build with MSBuild and set the Visual Studio version property
2017-03-23T23:49:31.0591599Z Version : 1.113.0
2017-03-23T23:49:31.0591599Z Author : Microsoft Corporation
2017-03-23T23:49:31.0591599Z Help : [More Information](https://go.microsoft.com/fwlink/?LinkID=613727)
2017-03-23T23:49:31.0591599Z ==============================================================================
2017-03-23T23:49:31.6529233Z Unable to determine the workspace. You may be able to correct this by running 'tf workspaces /collection:TeamProjectCollectionUrl'.
2017-03-23T23:49:31.8872843Z ##[error]Exit code 100 returned from process: file name 'tf', arguments 'vc resolvePath "$\My Development\Trunk\src\Rostering\trunk\[SOLUTION-NAME].sln" /loginType:OAuth /login:.,******** /noprompt'.
Any idea what causes this issue? We see no clear pattern when this happens. Our build server runs 24/7. It appears more likely to happen on the first build of the day.
The issue may related to the workspace, you could give a try with solution Error When Setting Clean = True on Windows
Looks like scorch is failing when the root sources folder (e.g. _work\1\s) is not mapped - i.e. workspace does not contain a root mapping. One not great workaround is to set a variable build.clean to all.