NuGet.exe swallows details of exception when parsing solution file

[alexangas]

Details about Problem

NuGet product used: NuGet.exe

NuGet version: current "dev" branch

dotnet.exe --version (if appropriate): N/A

VS version (if appropriate): N/A (VS14)

OS version (i.e. win10 v1607 (14393.321)): N/A (Windows 8.1)

Worked before? If so, with which NuGet version: No

Detailed repro steps so we can see the same problem

1. Prepare .sln file that has an issue that will cause a parsing error

2. Run nuget.exe restore xyz.sln

Expected results

Command line output containing details of parsing error:

Error parsing solution file at c:\Test\xyz.sln: Exception has been thrown by the target of an invocation. Error parsing the nested project section in solution file. A project with the GUID "{B24F8C45-D9B0-4EAC-9B5B-AFC11EC532A4}" is listed as being nested under project "{D2CBE02E-6AA7-4343-9A01-891F971A17F5}", but does not exist in the solution. c:\Test\xyz.sln

Actual results

Command line output with very little information:

Error parsing solution file at c:\Test\xyz.sln: Exception has been thrown by the target of an invocation.

...

Suggested solution

Change line 337 of MsBuildUtility.cs to include InnerException.Message. For example:

var message = string.Format(
	CultureInfo.CurrentCulture,
	LocalizedResourceManager.GetString("Error_SolutionFileParseError"),
	solutionFile,
	ex.Message + (ex.InnerException != null ? " " + ex.InnerException.Message : ""));

Happy to provide a pull request.

Sample Project

If necessary, I can provide one via a secure channel.