tfs - How to get TFS2015 Build (Build.vnext) and NuGet package restore to use custom package sources -

i'm trying our tfs2015 build (tfsbuild vnext) going along vs team services.

thus far blogs , documentation has been helpful, except when trying build project uses custom package sources nuget automatic package restore.

i've deployed team services build agent (the new mechanism builds) , seemed go until build task restore nuget packages failed.

the failure due custom/private package source not being picked installed vs configuration, packages not found. traditional packages default nuget package feed did restore without issue.

how specify additional package sources nuget use when using agent?

edit: vcastro asked nuget installer build step , defining paths in configuration of build step. above using visual studio build step , integrated option have nuget restore packages. refer image reference:

alternatively add nuget installer build step before visual studio build step in build configuration restore nuget packages.

there can pass location of private repo argument nuget.exe:

-source "https://www.nuget.org/api/v2/;http://mynugetserver"