In the above case I had a global.json file pointing to packages that are already checked in but even when pointing to myget I notice the following log and the packages aren't actually restored.
Restoring packages for C:\dd\WTE\src\Main\test\ProjectK\TestResults\Deploy_kanchanm 2014-11-25 15_01_44\Out\Tests_OnBuild_CoreCLR\TestSolution\UnitTest\UnitTestProject\project.json
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='Xunit.KRunner'.
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Runtime'.
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Runtime' 3709ms
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='Xunit.KRunner' 4094ms
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.IO'.
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Text.Encoding'.
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Collections'.
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Reflection'.
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Runtime.InteropServices'.
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.IO' 307ms
GET https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Threading.Tasks'.
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Threading.Tasks' 298ms
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Runtime.InteropServices' 1104ms
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Reflection' 1298ms
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Text.Encoding' 1550ms
OK https://www.myget.org/F/aspnetvnext/api/v2/FindPackagesById()?Id='System.Collections' 4012ms
Resolving complete, 8432ms elapsed
Restore complete, 8458ms elapsed
When the path where the project lives is too long (>260 char) package restore fails but doesn't show any errors.
For e.g. below none of the packages were restored but restore shows the following log -
In the above case I had a global.json file pointing to packages that are already checked in but even when pointing to myget I notice the following log and the packages aren't actually restored.