Paket


NuGet dependencies

Paket allows to reference NuGet packages in your application.

Sources

Sources are defined by the source <address> statement.

Paket supports multiple sources in one paket.dependencies. It's recommended to put all source statements at the top of paket.dependencies.

The paket.lock file will reflect the sources selected by dependency resolution.

NuGet feeds

Paket supports NuGet feeds like those provided by nuget.org, MyGet or TeamCity.

Please note that you need to specify all NuGet sources, including the default feed from nuget.org. Paket does not take the current machine's NuGet Package Sources configuration (that you set up e.g. using Visual Studio) into account.

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source https://nuget.org/api/v2     // nuget.org
source http://myserver/nuget/api/v2 // Custom feed.

It's also possible to provide login information for private NuGet feeds:

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source http://example.com/nuget/api/v2 username: "user name" password: "the password"

If you don't want to check your username and password into source control, you can use environment variables instead:

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source http://myserver/nuget/api/v2 username: "%PRIVATE_FEED_USER%" password: "%PRIVATE_FEED_PASS%"

%PRIVATE_FEED_USER% and %PRIVATE_FEED_PASS% will be expanded with the contents of your PRIVATE_FEED_USER and PRIVATE_FEED_PASS environment variables.

The paket.lock file will also reflect these settings.

Note: If paket.dependencies file exists while running the convert-from-nuget command, the PRIVATE_FEED_USER and PRIVATE_FEED_PASS will not be expanded. Please see this document for instructions on migrating credentials.

Path sources

Paket also supports file paths such as local directories or references to UNC shares:

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source C:\nugets
source ~/project/nugets
source \\server\share

Paket supports the source directory to be specified relative to the paket.dependencies file as well:

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source directory/relative/to/paket.dependencies

Dependencies

The dependencies of your project are defined by the nuget <package ID> <version constraint> statement.

Paket also supports file dependencies, such as referencing files directly from GitHub repositories.

Package ID

The package ID parameter is the same as you find in NuGet's packages.config or on nuget.org.

Version constraints

One key feature of Paket is that it separates the definition of dependencies from the actual resolution. NuGet stores resolution information in packages.config, where both package IDs and their respective pinned version are combined.

With Paket you do not need to pin specific versions (although you can). Paket allows you to leverage semantic versioning and define version constraints in a very flexible manner.

You can also influence the resolution of transitive dependencies.

Pinned version constraint

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nuget Example = 1.2.3
nuget Example 1.2.3   // Same as above.

nuget Example 1.2.3-alpha001

This is the strictest version constraint. Use the = operator to specify an exact version match; the = is optional.

Omitting the version constraint

If you omit the version constraint then Paket will assume >= 0:

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nuget Example

"Use exactly this version" constraint

We consider a situation with 3 packages A, B and C.

A and B are direct (or root-level) dependencies, but both have a dependency on C. A needs exactly C 1.0 and B wants version C 1.1. This is a version conflict and Paket will complain during resolution phase.

If we specify C = 1.1 in the paket.dependencies file then Paket still considers this as a version conflict with the version requirement in A. By specifying C == 1.1 we overwrite all other requirements and Paket will not complain about the conflict anymore.

If your transitive dependencies result in a version conflict you might want to instruct Paket to use a specific version. The == operator allows you to manually resolve the conflict:

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nuget Example == 1.2.3 // Take exactly this version.

Note: If you want to restrict the version to a specific version then use the = operator. The == operator should only be used if you need to overwrite a dependency resolution due to a conflict.

Further version constraints

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nuget Example >= 1.2.3       // At least 1.2.3
nuget Example > 1.2.3        // Greater than 1.2.3
nuget Example <= 1.2.3       // Less than or equal to 1.2.3
nuget Example < 1.2.3        // Less than 1.2.3
nuget Example >= 1.2.3 < 1.5 // At least 1.2.3 but less than 1.5

Pessimistic version constraint

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nuget Example ~> 1.2.3

The ~> "twiddle-wakka" operator is borrowed from bundler. It is used to specify a version range.

It translates to:

Use the minimum version specified, but allow upgrades up to, but not including, <version specified>, last part chopped off, last number incremented by 1.

In other words, allow the last part stated explicitly to increase, but pin any of the elements before that.

Let us illustrate:

Constraint

Version range

~> 0

0 <= x < 1

~> 1.0

1.0 <= x < 2.0

~> 1.2

1.2 <= x < 2.0

~> 1.2.3

1.2.3 <= x < 1.3

~> 1.2.3.4

1.2.3.4 <= x < 1.2.4

~> 1.2.3-alpha001

1.2.3-alpha001 <= x < 1.3

Pessimistic version constraint with compound

If want to allow newer backward-compatible versions but also need a specific fix version within the allowed range, use a compound constraint.

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nuget Example ~> 1.2 >= 1.2.3

The example above translates to 1.2.3 <= x < 2.0.

Prereleases

If you want to depend on prereleases then Paket can assist you. In contrast to NuGet, Paket allows you to depend on different prerelease channels:

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nuget Example >= 1.2.3 alpha  // At least 1.2.3 including alpha versions.
nuget Example >= 2 beta rc    // At least 2.0 including rc and beta versions.
nuget Example >= 3 rc         // At least 3.0 including rc versions.
nuget Example >= 3 prerelease // At least 3.0 including all prerelease versions.

Framework restrictions

Sometimes you do not want to generate dependencies for other .NET Framework versions than the ones your projects use. You can control this in the paket.dependencies file.

The framework modifier tells Paket to only consider the specified frameworks for a package:

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nuget Example >= 2.0 framework: net35, net40 // .NET 3.5 and .NET 4.0.

It translates to:

I use Example only to compile against net35 and net40. I never compile projects against another framework like net45.

Another example restricts to frameworks greater or equal than:

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nuget Example >= 2.0 framework: >= net45     // .NET 4.5 and above.

Note: This feature is deprecated and can be seen as an expert feature. Using framework restrictions on a single package might make you projects uncompilable. It is recommended to specify the frameworks you want to compile for globally or for a group).

Putting the version number in the path

If you need to be NuGet-compatible and want to have the package version number in the package path below packages you can do the following:

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source https://nuget.org/api/v2

nuget xunit.runner.visualstudio >= 2.0 version_in_path: true

Controlling whether content files should be copied to the project

The content modifier controls the installation of any content files:

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source https://nuget.org/api/v2

nuget jQuery content: none               // Do not install jQuery content files.
nuget Fody   content: once               // Install content files but do not overwrite.
nuget ServiceStack.Swagger content: true // Install content and always overwrite.

The default is content: true.

Controlling whether content files should be copied to the output directory during build

It's possible to influence the CopyToOutputDirectory property for content references via the copy_content_to_output_dir modifier:

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source https://nuget.org/api/v2

nuget jQuery copy_content_to_output_dir: always
nuget Fody copy_content_to_output_dir: never
nuget ServiceStack.Swagger copy_content_to_output_dir: preserve-newest

Controlling whether assemblies should be copied to the output directory during build

It's possible to influence the Private property for references via the copy_local modifier:

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source https://nuget.org/api/v2

nuget Newtonsoft.Json copy_local: false

The default is copy_local: true.

Importing *.targets and *.props files

If you don't want to import *.targets and *.props files from packages, you can disable it via the import_targets modifier:

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source https://nuget.org/api/v2

nuget Microsoft.Bcl.Build import_targets: false // Do not import *.targets and *.props.

Controlling assembly binding redirects

You can instruct Paket to create Assembly Binding Redirects for NuGet packages:

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source https://nuget.org/api/v2

nuget FSharp.Core redirects: on

Redirects are created only if they are required. However, you can instruct Paket to create them regardless:

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source https://nuget.org/api/v2

nuget FSharp.Core redirects: force

In contrast, you may force Paket to not create a redirect:

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source https://nuget.org/api/v2

nuget FSharp.Core redirects: off

You can also override the redirects settings per project, from its paket.references file.

Referencing specific versions in projects

It's possible to influence the SpecificVersion property for references via the specific_version modifier:

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source https://nuget.org/api/v2

nuget Newtonsoft.Json specific_version: false

Strategy modifiers

To override the strategy option you can use one of the strategy modifiers below.

Note, however, that all direct dependencies will still get their latest matching versions, no matter the value of the strategy option. If you want to influence the resolution of direct dependencies then read about the lowest_matching option.

The max modifier

To override the resolver strategy for the transitive dependencies of a package, use the strategy: max setting:

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strategy: min
source https://nuget.org/api/v2

nuget Example ~> 1.2 strategy: max

This effectively will get you the latest matching versions of Example's dependencies.

The following code is doing the same by using the @ operator in your version constraint:

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strategy: min
source https://nuget.org/api/v2

nuget Example @~> 1.2 // Use "max" version resolution strategy.

The min modifier

To override the resolver strategy for the transitive dependencies of a package, use the strategy: min modifier:

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source https://nuget.org/api/v2

nuget Example ~> 1.2 strategy: min

This effectively will get you the lowest matching versions of Example's dependencies. Still, you will get the latest matching version of Example itself according to its version constraint of 1.2 <= x <2.

The following code is doing the same by using the ! modifier in your version constraint:

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source https://nuget.org/api/v2

nuget Example !~> 1.2 // use "min" version resolution strategy

The strategy modifier and the corresponding ! and @ modifiers are applicable to all version constraints:

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source https://nuget.org/api/v2

nuget Example-A @> 0    // Use "max" version resolution strategy.
nuget Example-B != 1.2  // Use "min" version resolution strategy.
nuget Example-C !>= 1.2 // Use "min" version resolution strategy.
nuget Example-C >= 1.2 strategy: min

Resolver strategy for direct dependencies

To override the lowest_matching option you can use the following modifier.

Note, however, that all transitive dependencies will still get their latest matching versions, no matter the value of the lowest_matching modifier. If you want to influence the resolution of transitive dependencies then read about the strategy option.

To request Paket to override the resolver strategy for a package, use the lowest_matching: true modifier:

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source https://nuget.org/api/v2

nuget Example ~> 1.2 lowest_matching: true

Combine multiple modifiers

It is possible to apply more than one of the modifiers above to a particular package. To do so, simply separate them by commas:

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source https://nuget.org/api/v2

// Do not import .targets and .props and also do not add any content.
nuget ClearScript.Installer import_targets: false, content: none

Special case: dotnet CLI tools

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clitool dotnet-fable 1.17
nuget Fable.Core

Command line (CLI) tools that hook into the dotnet CLI are special NuGet packages. These packages are added with the keyword clitool instead of nuget. This will exclude the tool and all its dependencies from getting referenced as a dependency for any project.

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