How to Exclude Specific Files from NuGet Packages in C#

Understanding the Error: Duplicate Files in NuGet Packages Encountering the error message, "Payload contains two or more files with the same destination path..." during your C# project build process can be frustrating. This error, which often arises when packaging your application for deployment using NuGet, indicates that multiple files are trying to occupy the same destination location in your package. This situation typically occurs in environments where you have dependencies that might include common files, such as package.json and package-lock.json. When these files exist in both your project directory and within the libraries you are using (like the NuGet packages), the build process cannot decide which file to prioritize, resulting in a conflict condition. Root Causes of the Error Based on your situation, you're seeing this error potentially because: Multiple Sources: Both your project and the NuGet package are trying to include package.json and package-lock.json. This causes a conflict since they share the same destination path in the output. Package Structure: NuGet automatically includes certain files in the output package unless instructed otherwise. This can lead to issues if you haven't explicitly defined which files to include or exclude in your .csproj file. Steps to Exclude Files from the NuGet Package To resolve the conflict and prevent these files from being packaged, follow the steps below: Step 1: Modify the .csproj File Open your project’s .csproj file and include tags specifically targeting the files you want to exclude. Here’s how you can do it: Step 2: Use Pack Property Make sure to set the Pack property to false for these files so that they aren't included in the NuGet package. Full Example of a .csproj File Integrating everything, your modified .csproj file might look like this: mypackage net9.0 True README.md MIT Step 3: Rebuild the Project After making these changes, save your .csproj file and perform a clean build of your project. Run the following commands in your terminal: dotnet clean dotnet build This should eliminate the packaging errors related to duplicate files. Frequently Asked Questions What if I still see the error? If you still experience the same error after modifying your .csproj file, double-check that the paths specified for exclusion are correct and that there are no additional references to those files elsewhere in your project. Can I exclude other files too? Yes, you can apply a similar approach to exclude any files you don't want included in your NuGet package by using the tag with Pack":"false in your .csproj file. Will excluding files from NuGet affect my application? Excluding files from the NuGet package will ensure those files are not bundled with your application when you distribute it. Make sure these files are only needed during development and do not affect your application's runtime functionality. In conclusion, managing file conflicts during NuGet package creation can be tricky, but by properly configuring your .csproj and excluding unnecessary files, you can prevent build errors and create clean packages that meet your project's needs.

May 5, 2025 - 09:57

How to Exclude Specific Files from NuGet Packages in C#

Understanding the Error: Duplicate Files in NuGet Packages

Encountering the error message, "Payload contains two or more files with the same destination path..." during your C# project build process can be frustrating. This error, which often arises when packaging your application for deployment using NuGet, indicates that multiple files are trying to occupy the same destination location in your package.

This situation typically occurs in environments where you have dependencies that might include common files, such as package.json and package-lock.json. When these files exist in both your project directory and within the libraries you are using (like the NuGet packages), the build process cannot decide which file to prioritize, resulting in a conflict condition.

Root Causes of the Error

Based on your situation, you're seeing this error potentially because:

Multiple Sources: Both your project and the NuGet package are trying to include package.json and package-lock.json. This causes a conflict since they share the same destination path in the output.
Package Structure: NuGet automatically includes certain files in the output package unless instructed otherwise. This can lead to issues if you haven't explicitly defined which files to include or exclude in your .csproj file.

Steps to Exclude Files from the NuGet Package

To resolve the conflict and prevent these files from being packaged, follow the steps below:

Step 1: Modify the .csproj File

Open your project’s .csproj file and include tags specifically targeting the files you want to exclude. Here’s how you can do it:

Step 2: Use Pack Property

Make sure to set the Pack property to false for these files so that they aren't included in the NuGet package.

Full Example of a .csproj File

Integrating everything, your modified .csproj file might look like this:



  
    mypackage
    net9.0
    True
    README.md
    MIT

Step 3: Rebuild the Project

After making these changes, save your .csproj file and perform a clean build of your project. Run the following commands in your terminal:

dotnet clean
dotnet build

This should eliminate the packaging errors related to duplicate files.

Frequently Asked Questions

What if I still see the error?

If you still experience the same error after modifying your .csproj file, double-check that the paths specified for exclusion are correct and that there are no additional references to those files elsewhere in your project.

Can I exclude other files too?

Yes, you can apply a similar approach to exclude any files you don't want included in your NuGet package by using the tag with Pack":"false in your .csproj file.

Will excluding files from NuGet affect my application?

Excluding files from the NuGet package will ensure those files are not bundled with your application when you distribute it. Make sure these files are only needed during development and do not affect your application's runtime functionality.

In conclusion, managing file conflicts during NuGet package creation can be tricky, but by properly configuring your .csproj and excluding unnecessary files, you can prevent build errors and create clean packages that meet your project's needs.