NuGet pack and restore as MSBuild targets

NuGet 4.0+

NuGet 4.0+ can work directly with the information in a .csproj file without requiring a separate .nuspec or project.json file. All the metadata that was previously stored in those configuration files can be instead stored in the .csproj file directly, as described here.

With MSBuild 15.1+, NuGet is also a first-class MSBuild citizen with the pack and restore targets as described below. These targets allow you to work with NuGet as you would with any other MSBuild task or target. (For NuGet 3.x and earlier, you use the pack and restore commands through the NuGet CLI instead.)

In this topic:

Target build order

Because pack and restore are MSBuild targets, you can access them to enhance your workflow. For example, let’s say you want to copy your package to a network share after packing it. You can do that by adding the following in your project file:

<Target Name="CopyPackage" AfterTargets="Pack">
    <Copy
        SourceFiles="$(OutputPath)..\$(PackageId).$(PackageVersion).nupkg"
        DestinationFolder="\\myshare\packageshare\"
        />
</Target>

Similarly, you can write an MSBuild task, write your own target and consume NuGet properties in the MSBuild task.

pack target

When using the pack target, that is, msbuild /t:pack, MSBuild draws its inputs from the .csproj file rather than project.json or .nuspec files. The table below describes the MSBuild properties that can be added to a .csproj file within the first <PropertyGroup> node. You can make these edits easily in Visual Studio 2017 and later by right-clicking the project and selecting Edit {project_name} on the context menu. For convenience the table is organized by the equivalent property in a .nuspec file.

Note that the Owners and Summary properties from .nuspec are not supported with MSBuild.

Attribute/NuSpec Value MSBuild Property Default Notes
Id PackageId AssemblyName $(AssemblyName) from MSBuild
Version PackageVersion Version This is semver compatible, for example “1.0.0”, “1.0.0-beta”, or “1.0.0-beta-00345”
VersionPrefix PackageVersionPrefix empty Setting PackageVersion will overwrite PackageVersionPrefix
VersionSuffix PackageVersionSuffix empty $(VersionSuffix) from MSBuild. Setting PackageVersion will overwrite PackageVersionSuffix
Authors Authors Username of the current user
Owners N/A Not present in NuSpec
Title Title The PackageId
Description Description "Package Description"
Copyright Copyright empty
RequireLicenseAcceptance PackageRequireLicenseAcceptance false
LicenseUrl PackageLicenseUrl empty
ProjectUrl PackageProjectUrl empty
IconUrl PackageIconUrl empty
Tags PackageTags empty Tags are semi-colon delimited.
ReleaseNotes PackageReleaseNotes empty
RepositoryUrl RepositoryUrl empty
RepositoryType RepositoryType empty
PackageType <PackageType>DotNetCliTool, 1.0.0.0;Dependency, 2.0.0.0</PackageType>
Summary Not supported

pack target inputs

  • IsPackable
  • PackageVersion
  • PackageId
  • Authors
  • Description
  • Copyright
  • PackageRequireLicenseAcceptance
  • DevelopmentDependency
  • PackageLicenseUrl
  • PackageProjectUrl
  • PackageIconUrl
  • PackageReleaseNotes
  • PackageTags
  • PackageOutputPath
  • IncludeSymbols
  • IncludeSource
  • PackageTypes
  • IsTool
  • RepositoryUrl
  • RepositoryType
  • NoPackageAnalysis
  • MinClientVersion
  • IncludeBuildOutput
  • IncludeContentInPack
  • BuildOutputTargetFolder
  • ContentTargetFolders
  • NuspecFile
  • NuspecBasePath
  • NuspecProperties

pack scenarios

PackageIconUrl

As part of the change for NuGet Issue 2582, PackageIconUrl will eventually be changed to PackageIconUri and can be relative path to a icon file which will included at the root of the resulting package.

Output assemblies

nuget pack copies output files with extensions .exe, .dll, .xml, .winmd, .json, and .pri. The output files that are copied depend on what MSBuild provides from the BuiltOutputProjectGroup target.

There are two MSBuild properties that you can use in your project file or command line to control where output assemblies go:

  • IncludeBuildOutput: A boolean that determines whether the build output assemblies should be included in the package.
  • BuildOutputTargetFolder: Specifies the folder in which the output assemblies should be placed. The output assemblies (and other output files) are copied into their respective framework folders.

Package references

See Package References in Project Files.

Project to project references

Project to project references are considered by default as nuget package references, for example:

<ProjectReference Include="..\UwpLibrary2\UwpLibrary2.csproj"/>

You can also add the following metadata to your project reference:

<IncludeAssets>
<ExcludeAssets>
<PrivateAssets>

Including content in a package

To include content, add extra metadata to the existing <Content> item. By default everything of type "Content" gets included in the package unless you override with entries like the following:

   <Content Include="..\win7-x64\libuv.txt">
       <Pack>false</Pack>
   </Content>

By default, everything gets added to the root of the content and contentFiles\any\<target_framework> folder within a package and preserves the relative folder structure, unless you specify a package path:

<Content Include="..\win7-x64\libuv.txt">        
    <Pack>true</Pack>
    <PackagePath>content\myfiles\</PackagePath>
</Content>

If you want to copy all your content to only a specific root folder(s) (instead of content and contentFiles both), you can use the MSBuild property ContentTargetFolders, which defaults to "content;contentFiles" but can be set to any other folder names. Note that just specifying "contentFiles" in ContentTargetFolders puts files under contentFiles\any\<target_framework> or contentFiles\<language>\<target_framework> based on buildAction.

PackagePath can be a semicolon-delimited set of target paths. Specifying an empty package path would add the file to the root of the package. For example, the following adds libuv.txt to content\myfiles, content\samples, and the package root:

<Content Include="..\win7-x64\libuv.txt">
    <Pack>true</Pack>
    <PackagePath>content\myfiles;content\sample;;</PackagePath>
</Content>

There is also an MSBuild property $(IncludeContentInPack), which defaults to true. If this is set to false on any project, then the content from that project are not included in the nuget package.

Other pack specific metadata that you can set on any of the above items includes <PackageCopyToOutput> and <PackageFlatten> which sets CopyToOutput and Flatten values on the contentFiles entry in the output nuspec.

Note

Apart from Content items, the <Pack> and <PackagePath> metadata can also be set on files with a build action of Compile, EmbeddedResource, ApplicationDefinition, Page, Resource, SplashScreen, DesignData, DesignDataWithDesignTimeCreatableTypes, CodeAnalysisDictionary, AndroidAsset, AndroidResource, BundleResource or None.

For pack to append the filename to your package path when using globbing patterns, your package path must end with the folder separator character, otherwise the package path is treated as the full path including the file name.

IncludeSymbols

When using MSBuild /t:pack /p:IncludeSymbols=true, the corresponding .pdb files are copied along with other output files (.dll, .exe, .winmd, .xml, .json, .pri). Note that setting IncludeSymbols=true creates a regular package and a symbols package.

IncludeSource

This is the same as IncludeSymbols, except that it copies source files along with .pdb files as well. All files of type Compile are copied over to src\<ProjectName>\ preserving the relative path folder structure in the resulting package. The same also happens for source files of any ProjectReference which has TreatAsPackageReference set to false.

If a file of type Compile, is outside the project folder, then it is just added to src\<ProjectName>\.

IsTool

When using MSBuild /t:pack /p:IsTool=true, all output files, as specified in the Output Assemblies scenario, are copied to the tools folder instead of the lib folder. Note that this is different from a DotNetCliTool which is specified by setting the PackageType in .csproj file.

Packing using a .nuspec

You can use a .nuspec file to pack your project provided that you have a project file to import NuGet.Build.Tasks.Pack.targets so that the pack task can be executed. The following three MSBuild properties are relevant to packing using a .nuspec:

  1. NuspecFile: relative or absolute path to the .nuspec file being used for packing.
  2. NuspecProperties: a semicolon-separated list of key=value pairs. Due to the way MSBuild command-line parsing works, multiple properties must be specified as follows: /p:NuspecProperties=\"key1=value1;key2=value2\".
  3. NuspecBasePath: Base path for the .nuspec file.

If using dotnet.exe to pack your project, use a command like the following:

dotnet pack <path to .csproj file> /p:NuspecFile=<path to nuspec file> /p:NuspecProperties=<> /p:NuspecBasePath=<Base path> 

If using MSBuild to pack your project, use a command like the following:

msbuild /t:pack <path to .csproj file> /p:NuspecFile=<path to nuspec file> /p:NuspecProperties=<> /p:NuspecBasePath=<Base path> 

restore target

MSBuild /t:restore (which nuget restore and dotnet restore use with .NET Core projects), restores packages referenced in the project file as follows:

  1. Read all project to project references
  2. Read the project properties to find the intermediate folder and target frameworks
  3. Pass msbuild data to NuGet.Build.Tasks.dll
  4. Run restore
  5. Download packages
  6. Write assets file, targets, and props

Restore properties

Additional restore settings may come from MSBuild properties in the project file. Values can also be set from the command line using the /p: switch (see Examples below).

Property Description
RestoreSources Semicolon-delimited list of package sources.
RestorePackagesPath User packages folder path.
RestoreDisableParallel Limit downloads to one at a time.
RestoreConfigFile Path to a Nuget.Config file to apply.
RestoreNoCache If true, avoids using the web cache.
RestoreIgnoreFailedSources If true, ignores failing or missing package sources.
RestoreTaskAssemblyFile Path to NuGet.Build.Tasks.dll.
RestoreGraphProjectInput Semicolon-delimited list of projects to restore, which should contain absolute paths.
RestoreOutputPath Output folder, defaulting to the obj folder.

Examples

Command line:

msbuild /t:restore /p:RestoreConfigFile=<path>

Project file:

<PropertyGroup>
    <RestoreIgnoreFailedSource>true</RestoreIgnoreFailedSource>
<PropertyGroup>

Restore outputs

Restore creates the following files in the build obj folder:

File Description
project.assets.json Previously project.lock.json
{projectName}.projectFileExtension.nuget.g.props References to MSBuild props contained in packages
{projectName}.projectFileExtension.nuget.g.targets References to MSBuild targets contained in packages

PackageTargetFallback

The PackageTargetFallback element allows you to specify a set of compatible targets to be used when restoring packages (the equivalent of imports in project.json). It's designed to allow packages that use a dotnet TxM to work with compatible packages that don't declare a dotnet TxM. That is, if your project uses the dotnet TxM, then all the packages it depends on must also have a dotnet TxM, unless you add the <PackageTargetFallback> to your project in order to allow non-dotnet platforms to be compatible with dotnet.

For example, if the project is using the netstandard1.6 TxM, and a dependent package contains only lib/net45/a.dll and lib/portable-net45+win81/a.dll, then the project will fail to build. If what you want to bring in is the latter DLL, then you can add a PackageTargetFallback as follows to say that the portable-net45+win81 DLL is compatible:

<PackageTargetFallback Condition="'$(TargetFramework)'=='netstandard1.6'">
    portable-net45+win81
</PackageTargetFallback>

To declare a fallback for all targets in your project, leave off the Condition attribute. You can also extend any existing PackageTargetFallback by including $(PackageTargetFallback) as shown here:

<PackageTargetFallback>
    $(PackageTargetFallback);portable-net45+win81
</PackageTargetFallback >

Replacing one library from a restore graph

If a restore is bringing the wrong assembly, it is possible to exclude that packages default choice, and replace it with your own choice. First with a top level PackageReference, exclude all assets:

<PackageReference Include="Newtonsoft.Json" Version="9.0.1">
    <ExcludeAssets>All</ExcludeAssets>
</PackageReference>

Next, add your own reference to the appropriate local copy of the DLL:

<Reference Include="Newtonsoft.Json.dll" />