A LocalPackageRepository for NuGet that continues to work when packages are being written to it

gistfile1.cs

/// <summary>
/// The local package repository (used for reading packages from the file system) is broken in NuGet.Core because 
/// when a package is being written, it refuses to read the packages. This implementation wraps it by ignoring packages
/// that can't be written (either because they are locked or only partially written). 
/// </summary>
public class FastLocalPackageRepository : LocalPackageRepository
{
    readonly ILog log;

    public FastLocalPackageRepository(string physicalPath, ILog log)
        : base(physicalPath)
    {
        this.log = log;
    }

    protected override IPackage OpenPackage(string path)
    {
        var fullPath = FileSystem.GetFullPath(path);

        try
        {
            return new ZipPackage(fullPath);
        }
        catch (Exception ex)
        {
            log.Warn("Unable to read NuGet package file: " + fullPath + " -- it will be ignored. Error: " + ex.Message, ex);
            return new NullPackage();
        }
    }

    public override IQueryable<IPackage> GetPackages()
    {
        return base.GetPackages().Where(p => p is NullPackage == false);
    }

    /// <summary>
    /// Represents a package file that cannot be read.
    /// </summary>
    public class NullPackage : IPackage
    {
        public NullPackage()
        {
            Id = "null";
            Version = new SemanticVersion("0.0.0.0");
        }

        public string Id { get; private set; }
        public SemanticVersion Version { get; private set; }
        public string Title { get; private set; }
        public IEnumerable<string> Authors { get; private set; }
        public IEnumerable<string> Owners { get; private set; }
        public Uri IconUrl { get; private set; }
        public Uri LicenseUrl { get; private set; }
        public Uri ProjectUrl { get; private set; }
        public bool RequireLicenseAcceptance { get; private set; }
        public string Description { get; private set; }
        public string Summary { get; private set; }
        public string ReleaseNotes { get; private set; }
        public string Language { get; private set; }
        public string Tags { get; private set; }
        public string Copyright { get; private set; }
        public IEnumerable<FrameworkAssemblyReference> FrameworkAssemblies { get; private set; }
        public IEnumerable<PackageDependencySet> DependencySets { get; private set; }
        public Uri ReportAbuseUrl { get; private set; }
        public int DownloadCount { get; private set; }
        public IEnumerable<IPackageFile> GetFiles()
        {
            throw new NotImplementedException();
        }

        public IEnumerable<FrameworkName> GetSupportedFrameworks()
        {
            throw new NotImplementedException();
        }

        public Stream GetStream()
        {
            throw new NotImplementedException();
        }

        public bool IsAbsoluteLatestVersion { get; private set; }
        public bool IsLatestVersion { get; private set; }
        public bool Listed { get; private set; }
        public DateTimeOffset? Published { get; private set; }
        public IEnumerable<IPackageAssemblyReference> AssemblyReferences { get; private set; }
    }
}