Suppress Build Output When Running `dotnet run`

Question

Is it possible to suppress the build warnings which are output when dotnet run causes a build to occur, e.g. after a code change?

$ dotnet run --verbosity quiet

/../MyProgram.cs(6,21): warning CS8618: Non-nullable property
    'MyProperty' must contain a non-null value when exiting
    constructor. Consider declaring the property as nullable.

<My Program Output>

This is painful, as during development I will pipe my program output into another tool, and the build warning output breaks the parsing of that tool. I don't want to disable any particular warnings; I want to simply omit them from the output of dotnet run.

Answer 1

$ dotnet run --property WarningLevel=0

• --property:<NAME>=<VALUE> to pass properties to MSBuild (https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-run)
• WarningLevel=[0,1,2,3,4] to configure the level of warnings to be output where 4 is the default and 0 disables all warnings (https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/compiler-options/errors-warnings)

Answer 2

I have found that you need multiple switches for this to work more reliably:

dotnet build --nologo -v q --property WarningLevel=0 /clp:ErrorsOnly

where:

• --nologo suppresses the header
• -v q sets output verbosity to quiet
• --property WarningLevel=0 is for MsBuild, and described well in other answers.
• /clp:ErrorsOnly means ConsoleLoggerParameters

For reasons, I have not fully explored, dotnet run does not always respect these arguments, so I stitch these together with bash/pwsh:

dotnet build --nologo -v q --property WarningLevel=0 /clp:ErrorsOnly && dotnet run --no-build

Disclaimer: disabling warnings is a generally a bad idea