Nuspec defines an optional targetFramework attribute as of version 2.0
When uploading a nupkg with a nuspec containing this attribute, Nexus does not expose the framework bits in the feed <p:dependencies> element, therefore installing these artifacts from a local nuget repo using visual studio does not work.
In contrast, downloading a nupkg from a _proxy_ repository feed WILL work because these dependency details include targetFramework details.
1) Download a nupkg which specifies dependencies with targetFramework
Results in a file called microsoft.aspnet.webapi.client.5.0.0.nupkg
1) Boot nexus Pro
2) Add a local repo of Nuget type
3) Using the artifact upload tab, upload the nuget artifact into the local nuget repo.
4) Perform a search against that local nuget repo for the uploaded artifact. The feed entry returned will not contain the targetFramework string inside the dependency element.
Compare this with a proxy Nuget repo of the official feed:
1) in nexus, add a proxy repo against https://www.nuget.org/api/v2
2) wait for the download nuget index task to complete ( approx 5-6 minutes )
3) Perform a search against that proxy nuget repo for the same artifact. The feed entry returned will contain the targetFramework string inside the dependency element.
Attached files contain the detailed differences: