Use environment variable in NuGet config?

Question

Is there a way to use an environment variable in NuGet.Config file?

Currently I am constrained to using relative path, as follows:

<configuration>
  <config>       
    <add key="repositoryPath" value="..\..\teampackages" />
  </config>
</configuration>

But would be really handy to have an environment variable with absolute path instead.

Answer 1

If you run nuget pack MyProject.csproj on a project with a corresponding MyProject.nuspec file in the same directory, NuGet will make the MSBuild properties available as tokens in the format $Property$, where Property is the name of the MSBuild property. For example:

<?xml version="1.0"?>
<package >
  <metadata>
    <id>$id$</id>
    <version>$version$</version>
    <title>$title$</title>
    <authors>$author$</authors>
    <owners>$author$</owners>
    <requireLicenseAcceptance>false</requireLicenseAcceptance>
    <description>$description$</description>
    <copyright>Copyright 2013</copyright>
  </metadata>
  <files>
    <file src="$OutputPath$MyProject.pdb" target="lib\net40"/>
  </files>
</package>

In this example $id$, $version$, $title$, $author$ and $description$ are special values provided by NuGet itself based on the project file and AssemblyVersion attribute (normally found in AssemblyInfo.cs). However, $OutputPath$ is an MSBuild property defined in the common targets. You could also use $MSBuildProjectDirectory$ or any other standard property.

More info here ("Replacement Tokens" section):

NuSpec Reference