I use SVN to checkout a project to .\proj and a dependency to .\dep. The .sln file is at .\proj\proj.sln. I us the MsBuild plugin with the setting "MsBuild Build File" = "proj\proj.sln" (or a number of variants such as .\proj\proj.sln). Msbuild fails with MSB1009: Project file does not exist. However, running a similar command manually succeeds.