git-ecosystem/git-credential-manager · error · ArgumentException

A cancelled or yielded response cannot carry a credential.

Error message

A cancelled or yielded response cannot carry a credential.

What it means

GitResponse's constructor also forbids a Cancelled or Yielded response from carrying a credential: cancelling or yielding means no credential is offered to the caller, so attaching one is contradictory and throws ArgumentException with nameof(credential). A non-cancelled, non-yielded response without a credential is separately rejected.

Solutions

1. Pass null for credential when the response is cancelled or yielded.
2. Restructure provider code so cancellation is detected before credential acquisition, or discard the credential when returning Cancel/Yield.
3. Use the static factory helpers (e.g. Cancel()) that do not accept credentials.

Example fix

// before
return new GitResponse(credential, isCancelled: true);
// after
return new GitResponse(null, isCancelled: true); // or GitResponse.Cancel()

if ((isCancelled || isYielded) && credential is not null)
    throw new InvalidOperationException("Drop the credential before returning Cancel/Yield.");

bool IsValidResponse(string credential, bool cancelled, bool yielded) =>
    (cancelled || yielded) ? credential is null : credential is not null;

try
{
    var response = new GitResponse(credential, isCancelled: cancelled);
}
catch (ArgumentException ex) when (ex.Message.Contains("cannot carry a credential"))
{
    // return GitResponse.Cancel() without the credential instead
}

When it happens

Trigger: Constructing GitResponse with isCancelled or isYielded true while passing a non-null credential object, e.g. new GitResponse(credential, isCancelled: true) from provider code that fetches a credential and then decides to cancel without dropping the credential.

Common situations: Provider implementations that obtain a credential first and later detect cancellation/yield conditions; error paths that wrap an existing credential into a cancel response; copy-paste from success-path constructors.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• A response can be at most one of Continue, Cancel, or Yield.
• Cannot render the None capability to a protocol name.
• Must specify at least one AuthenticationModes
• Argument cannot be empty.
• Argument cannot be empty or white space.

AI-assisted analysis of git-ecosystem/git-credential-manager@e8ce762cd0 (2026-09-11). Data as JSON: /api/errors/e90c771a1714e926. Report an issue: GitHub.

Appendix: source

Thrown at src/Core/GitResponse.cs:61

    private readonly Dictionary<string, string> _state = new(StringComparer.Ordinal);
    private ReadOnlyDictionary<string, string> _stateView;

    private GitResponse(ICredential credential, bool isContinue, bool isCancelled, bool isYielded)
    {
        // At most one of Continue, Cancel, Yield may be set (Ok is "none of them").
        if ((isContinue && isCancelled) ||
            (isContinue && isYielded) ||
            (isCancelled && isYielded))
        {
            throw new ArgumentException(
                "A response can be at most one of Continue, Cancel, or Yield.");
        }

        bool hasCredential = credential is not null;

        if ((isCancelled || isYielded) && hasCredential)
        {
            throw new ArgumentException(
                "A cancelled or yielded response cannot carry a credential.",
                nameof(credential));
        }

        if (!isCancelled && !isYielded && !hasCredential)
        {
            throw new ArgumentNullException(
                nameof(credential),
                "A non-cancelled, non-yielded response must carry a credential. Use Cancel() or Yield() instead.");
        }

        Credential = credential;
        IsContinue = isContinue;
        IsCancelled = isCancelled;
        IsYielded = isYielded;
    }

    /// <summary>

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