microsoft/aspire · error · InvalidOperationException

Invalid value " " for "--dcp-dependency-check-timeout"…

Error message

Invalid value "{dcpPublisherConfiguration[nameof(options.DependencyCheckTimeout)]}" for "--dcp-dependency-check-timeout". Expected an integer value.

What it means

DcpOptions.Configure parses the --dcp-dependency-check-timeout configuration value and requires it to be a valid integer. When the configured string exists but cannot be parsed by int.TryParse, it throws this InvalidOperationException instead of silently ignoring the value. This fails fast so a typo does not silently produce a default timeout.

Solutions

Set --dcp-dependency-check-timeout to a plain integer of seconds, e.g. --dcp-dependency-check-timeout 90
Remove the flag entirely to fall back to the DependencyCheckTimeout default or the KnownConfigNames.DependencyCheckTimeout value
Check appsettings/environment config for the DcpPublisher:DependencyCheckTimeout key and fix it to an integer

Example fix

// before
dotnet run --dcp-dependency-check-timeout 90s
// after
dotnet run --dcp-dependency-check-timeout 90

Defensive patterns

Strategy: validation

Validate before calling

var value = configuration["DcpPublisher:DependencyCheckTimeout"];
if (value is not null && !int.TryParse(value, out _))
{
    throw new FormatException($"'{value}' is not a valid integer for --dcp-dependency-check-timeout.");
}

Type guard

bool IsValidTimeoutValue(string? v) => v is null || int.TryParse(v, out _);

Try / catch

try
{
    options.Configure(configuration);
}
catch (InvalidOperationException ex) when (ex.Message.Contains("--dcp-dependency-check-timeout"))
{
    // Fall back to default timeout or surface a corrected value.
    options.DependencyCheckTimeout = 60;
}

Prevention

Always pass whole seconds as a plain integer, never "90s" or TimeSpan strings
Validate config values in CI before launching the AppHost
Prefer omitting the flag to use the built-in default

When it happens

Trigger: Setting --dcp-dependency-check-timeout (or DcpPublisher:DependencyCheckTimeout config key) to a non-integer string such as "30s", "00:00:30", "thirty", or a value with whitespace/units.

Common situations: Passing a TimeSpan-formatted value like "00:01:00" or "90s" on the command line or in appsettings.json expecting it to be parsed as a duration; copy-pasting values with trailing characters.

Understand the failure class

Background: "is not a valid" / "Invalid ... value" environment variable errors: how libraries validate env vars and what to do when they reject yours — this error's family across 48 libraries.

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of microsoft/aspire@25830f84bd (2026-09-16). Data as JSON: /api/errors/3ba5605881c09ee2. Report an issue: GitHub.

Appendix: source

Thrown at src/Aspire.Hosting/Dcp/DcpOptions.cs:324

        if (!string.IsNullOrEmpty(dcpPublisherConfiguration[nameof(options.ContainerRuntime)]))
        {
            options.ContainerRuntime = dcpPublisherConfiguration[nameof(options.ContainerRuntime)];
        }
        else
        {
            options.ContainerRuntime = configuration.GetString(KnownConfigNames.ContainerRuntime, KnownConfigNames.Legacy.ContainerRuntime);
        }

        if (!string.IsNullOrEmpty(dcpPublisherConfiguration[nameof(options.DependencyCheckTimeout)]))
        {
            if (int.TryParse(dcpPublisherConfiguration[nameof(options.DependencyCheckTimeout)], out var timeout))
            {
                options.DependencyCheckTimeout = timeout;
            }
            else
            {
                throw new InvalidOperationException($"Invalid value \"{dcpPublisherConfiguration[nameof(options.DependencyCheckTimeout)]}\" for \"--dcp-dependency-check-timeout\". Expected an integer value.");
            }
        }
        else
        {
            options.DependencyCheckTimeout = configuration.GetValue(KnownConfigNames.DependencyCheckTimeout, KnownConfigNames.Legacy.DependencyCheckTimeout, options.DependencyCheckTimeout);
        }

        options.KubernetesConfigReadRetryCount = dcpPublisherConfiguration.GetValue(nameof(options.KubernetesConfigReadRetryCount), options.KubernetesConfigReadRetryCount);
        options.KubernetesConfigReadRetryIntervalMilliseconds = dcpPublisherConfiguration.GetValue(nameof(options.KubernetesConfigReadRetryIntervalMilliseconds), options.KubernetesConfigReadRetryIntervalMilliseconds);

        if (!string.IsNullOrEmpty(dcpPublisherConfiguration[nameof(options.ResourceNameSuffix)]))
        {
            options.ResourceNameSuffix = dcpPublisherConfiguration[nameof(options.ResourceNameSuffix)];
        }

        options.RandomizePorts = dcpPublisherConfiguration.GetValue(nameof(options.RandomizePorts), options.RandomizePorts);
        options.ProxylessEndpointPortRangeStart = dcpPublisherConfiguration.GetValue(nameof(options.ProxylessEndpointPortRangeStart), options.ProxylessEndpointPortRangeStart);
        options.ProxylessEndpointPortRangeEnd = dcpPublisherConfiguration.GetValue(nameof(options.ProxylessEndpointPortRangeEnd), options.ProxylessEndpointPortRangeEnd);

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