stride3d/stride · error · InvalidOperationException

Ambiguous project name

Error message

Ambiguous project name '{_request.Project.Name}'.

What it means

Inside GetProjectReferences, the helper matches the requested project name against the list of projects in the MSBuild workspace/closure. If more than one project matches the same name case-insensitively, the match is ambiguous and an InvalidOperationException is thrown rather than guessing which project to use.

Solutions

  1. Rename the duplicate project so each project name in the session is unique
  2. Use the PackageSpecProjectName (full unique name) instead of the plain project name when resolving
  3. Remove or unload the duplicate project from the solution/session

Example fix

// before: two projects named 'MyGame' in different folders
// after: rename one and rebuild
<AssemblyName>MyGame.Tests</AssemblyName> <!-- in the duplicate csproj -->
Defensive patterns

Strategy: validation

Validate before calling

var names = session.Projects.Select(p => p.Name);
if (names.GroupBy(n => n, StringComparer.OrdinalIgnoreCase).Any(g => g.Count() > 1))
    logger.Warning("Duplicate project names in session; rename before resolving references");

Try / catch

try { ResolveProjectReferences(request); }
catch (InvalidOperationException ex) when (ex.Message.StartsWith("Ambiguous project name"))
{ logger.Error(ex, "Rename duplicate projects"); }

Prevention

When it happens

Trigger: Requesting external/project references for a project whose Name matches multiple projects loaded in the session/workspace (duplicate project names across different folders or solution configurations).

Common situations: Two .csproj files with the same assembly/project name in different directories, a solution containing a project and its tests with identical names, duplicated projects from nested package references.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/b366a015f2178f08. Report an issue: GitHub.

Appendix: source

Thrown at sources/assets/Stride.Core.Assets/PackageSession.Dependencies.cs:621

        if (_request.ExternalProjects.Count == 0)
        {
            // If no projects exist add the current project.json file to the project
            // list so that it can be resolved.
            updatedExternalProjects.Add(ToExternalProjectReference(_request.Project));
        }
        else if (_request.ExternalProjects.Count > 0)
        {
            // There should be at most one match in the external projects.
            var rootProjectMatches = _request.ExternalProjects.Where(proj =>
                    string.Equals(
                        _request.Project.Name,
                        proj.PackageSpecProjectName,
                        StringComparison.OrdinalIgnoreCase))
                    .ToList();

            if (rootProjectMatches.Count > 1)
            {
                throw new InvalidOperationException($"Ambiguous project name '{_request.Project.Name}'.");
            }

            var rootProject = rootProjectMatches.SingleOrDefault();

            if (rootProject != null)
            {
                // Replace the project spec with the passed in package spec,
                // for installs which are done in memory first this will be
                // different from the one on disk
                updatedExternalProjects.AddRange(_request.ExternalProjects
                    .Where(project =>
                        !project.UniqueName.Equals(rootProject.UniqueName, StringComparison.Ordinal)));

                var updatedReference = new ExternalProjectReference(
                    rootProject.UniqueName,
                    _request.Project,
                    rootProject.MSBuildProjectPath,
                    rootProject.ExternalProjectReferences);

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