dotnet/BenchmarkDotNet · error · ArgumentException

Property name must be non-empty.

Error message

Property name must be non-empty.

What it means

MsBuildProperty's constructor requires a non-empty property name; CreateArgumentTextRepresentation throws ArgumentException ("Property name must be non-empty.") when name is null, empty, or whitespace. The name becomes part of the /p:NAME=value MSBuild argument and must be a real identifier.

Source

Thrown at src/BenchmarkDotNet/Jobs/Argument.cs:123

    }

    /// <summary>
    /// An MSBuild property argument (<c>/p:name=value</c>).
    /// It escapes MSBuild special characters in the value (for example, semicolons) so that
    /// list-like values can be passed without manual encoding.
    /// </summary>
    [PublicAPI]
    public class MsBuildProperty : MsBuildArgument
    {
        public MsBuildProperty(string name, params string[] values)
            : base(CreateArgumentTextRepresentation(name, values), escapeSpecialCharacters: true)
        {
        }

        private static string CreateArgumentTextRepresentation(string name, string[] values)
        {
            if (string.IsNullOrWhiteSpace(name))
                throw new ArgumentException("Property name must be non-empty.", nameof(name));

            if (values is null)
                throw new ArgumentNullException(nameof(values));

            for (int i = 0; i < values.Length; i++)
                if (values[i] is null)
                    throw new ArgumentException("Property values can not contain null.", nameof(values));

            string value = values.Length switch
            {
                0 => string.Empty,
                1 => values[0],
                _ => string.Join(";", values)
            };

            return $"/p:{name}={value}";
        }
    }

View on GitHub (pinned to b515068b61)

Solutions

1. Provide a concrete non-empty property name, e.g. new MsBuildProperty("MyCustomSetting", "123").
2. Validate with !string.IsNullOrWhiteSpace(name) before constructing the MsBuildProperty.
3. If the name is optional, skip adding the property entirely rather than passing empty.

Example fix

// before
job.WithArgument(new MsBuildProperty("", "123"));

// after
job.WithArgument(new MsBuildProperty("MyCustomSetting", "123"));

if (string.IsNullOrWhiteSpace(name)) throw new ArgumentException("name required");
job.WithArgument(new MsBuildProperty(name, value));

When it happens

Trigger: Calling new MsBuildProperty("", ...) or new MsBuildProperty(" ", ...) (or null name) when adding an MSBuild property to a benchmark job.

Common situations: Building property names dynamically from config/variables that may be unset, whitespace from trimmed input, or copy-paste leaving an empty name.

Related errors

• String cannot be empty.
• Value cannot be null. (Parameter 'values')
• The value {value} is not assignable to {characteristic} prop
• String cannot be empty or whitespace.
• Runtime Moniker not supported

AI-assisted analysis of dotnet/BenchmarkDotNet@b515068b61 (2026-08-13). Data as JSON: /api/errors/fdd983dbaae2a8fc. Report an issue: GitHub.