How to use the command dotnet restore (with examples)

The dotnet restore command is used to restore the dependencies and tools of a .NET project. It retrieves the packages required by the project from the NuGet package cache or the sources specified in the project file. This command is typically used before building or running a .NET project to ensure that all necessary dependencies are available.

Use case 1: Restore dependencies for a .NET project or solution in the current directory

Code:

dotnet restore

Motivation: This command is used when you want to restore the dependencies for a .NET project or solution that is located in the current directory. It will look for the project or solution files in the current directory and restore all the required packages.

Explanation: This command does not require any additional arguments or options. It simply looks for the project or solution files in the current directory and restores the dependencies.

Example output:

...
Restoring packages for C:/path/to/project.csproj...
Installing Microsoft.AspNetCore 3.1.5.
...
Done.

Use case 2: Restore dependencies for a .NET project or solution in a specific location

Code:

dotnet restore path/to/project_or_solution

Motivation: This command is useful when you want to restore the dependencies for a .NET project or solution that is located in a specific directory. Instead of searching in the current directory, you can provide the path to the project or solution file and the command will restore the dependencies for that specific project or solution.

Explanation: The path/to/project_or_solution argument specifies the path to the .NET project or solution file. This can be a relative or absolute path. The command will search for the project or solution file in the specified location and restore the dependencies.

Example output:

...
Restoring packages for C:/path/to/project.csproj...
Installing Microsoft.AspNetCore 3.1.5.
...
Done.

Use case 3: Restore dependencies without caching the HTTP requests

Code:

dotnet restore --no-cache

Motivation: By default, the dotnet restore command caches the HTTP requests made to retrieve the packages. This can speed up subsequent restores if the packages have not changed. However, there might be situations where you want to disable the cache and force the command to retrieve the packages from the source every time.

Explanation: The --no-cache option disables the caching of HTTP requests made during the restore process. When this option is specified, the command will always retrieve the packages from the source, even if they are already present in the cache.

Example output:

...
Restoring packages for C:/path/to/project.csproj...
HTTP GET https://api.nuget.org/v3/index.json
Installing Microsoft.AspNetCore 3.1.5.
...
Done.

Use case 4: Force all dependencies to be resolved even if the last restore was successful

Code:

dotnet restore --force

Motivation: Sometimes, the restore process might skip certain dependencies if they are already present in the cache and the restore was successful in the last run. However, there could be situations where you want to ensure that all dependencies are resolved and retrieved, even if they are already present in the cache.

Explanation: The --force option forces the command to resolve and retrieve all dependencies, even if they are already present in the cache and the last restore was successful. This can be useful if you suspect that some dependencies might be missing or outdated in the cache.

Example output:

...
Restoring packages for C:/path/to/project.csproj...
Cache hit for Microsoft.AspNetCore 3.1.5.
Installing Microsoft.AspNetCore 5.0.0.
...
Done.

Use case 5: Restore dependencies using package source failures as warnings

Code:

dotnet restore --ignore-failed-sources

Motivation: When restoring dependencies, if a package source fails to provide a required package, the restore process will fail. However, in some cases, you might want to continue the restore process and treat package source failures as warnings instead of errors.

Explanation: The --ignore-failed-sources option allows the command to continue the restore process even if a package source fails to provide a required package. Rather than failing the restore process, the failures are treated as warnings and the process continues with the available packages.

Example output:

...
Restoring packages for C:/path/to/project.csproj...
WARNING: Unable to resolve package 'MyPackage' from source 'https://my.package.source'.
Installing Microsoft.AspNetCore 3.1.5.
...
Done.

Use case 6: Restore dependencies with a specific verbosity level

Code:

dotnet restore --verbosity quiet|minimal|normal|detailed|diagnostic

Motivation: The verbosity level determines the amount of information displayed during the restore process. By default, the verbosity level is set to “normal”. However, you may want to adjust the verbosity level depending on the amount of detail you require.

Explanation: The --verbosity option allows you to specify the verbosity level for the restore process. The available levels are:

• quiet: Displays no output except for error messages.
• minimal: Displays minimal output with only essential information.
• normal (default): Displays standard output with progress information.
• detailed: Displays more detailed output with additional information.
• diagnostic: Displays diagnostic output with extensive details.

Example output (using --verbosity minimal):

Restoring...
Done.

Conclusion

The dotnet restore command is a powerful tool for restoring the dependencies and tools of a .NET project. It provides various options and arguments to customize the restore process according to your needs. Whether you want to restore dependencies for a project in the current directory, a specific location, or with specific behaviors, the dotnet restore command has you covered. By understanding the different use cases and examples provided in this article, you can effectively utilize this command for your .NET projects.