@@ -55,7 +55,7 @@ namespace OpenTelemetry.Exporter.OpenTelemetryProtocol.Implementation.ExportClie
             }
             catch (HttpRequestException ex)
             {
-                OpenTelemetryProtocolExporterEventSource.Log.FailedToReachCollector(ex);
+                OpenTelemetryProtocolExporterEventSource.Log.FailedToReachCollector(this.Options.Endpoint, ex);
 
                 return false;
             }
// <copyright file="BaseOtlpHttpExportClient.cs" company="OpenTelemetry Authors">
// Copyright The OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// </copyright>

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading;
using OpenTelemetry.Internal;

namespace OpenTelemetry.Exporter.OpenTelemetryProtocol.Implementation.ExportClient
{
    /// <summary>Base class for sending OTLP export request over HTTP.</summary>
    /// <typeparam name="TRequest">Type of export request.</typeparam>
    internal abstract class BaseOtlpHttpExportClient<TRequest> : IExportClient<TRequest>
    {
        protected BaseOtlpHttpExportClient(OtlpExporterOptions options, HttpClient httpClient = null)
        {
            Guard.Null(options, nameof(options));
            Guard.InvalidTimeout(options.TimeoutMilliseconds, $"{nameof(options)}.{nameof(options.TimeoutMilliseconds)}");

            this.Options = options;
            this.Headers = options.GetHeaders<Dictionary<string, string>>((d, k, v) => d.Add(k, v));
            this.HttpClient = httpClient ?? new HttpClient { Timeout = TimeSpan.FromMilliseconds(this.Options.TimeoutMilliseconds) };
        }

        internal OtlpExporterOptions Options { get; }

        internal HttpClient HttpClient { get; }

        internal IReadOnlyDictionary<string, string> Headers { get; }

        /// <inheritdoc/>
        public bool SendExportRequest(TRequest request, CancellationToken cancellationToken = default)
        {
            try
            {
                using var httpRequest = this.CreateHttpRequest(request);

                using var httpResponse = this.SendHttpRequest(httpRequest, cancellationToken);

                httpResponse?.EnsureSuccessStatusCode();
            }
            catch (HttpRequestException ex)
            {
                OpenTelemetryProtocolExporterEventSource.Log.FailedToReachCollector(ex);

                return false;
            }

            return true;
        }

        /// <inheritdoc/>
        public bool Shutdown(int timeoutMilliseconds)
        {
            this.HttpClient.CancelPendingRequests();
            return true;
        }

        protected abstract HttpRequestMessage CreateHttpRequest(TRequest request);

        protected HttpResponseMessage SendHttpRequest(HttpRequestMessage request, CancellationToken cancellationToken)
        {
#if NET5_0_OR_GREATER
            return this.HttpClient.Send(request, cancellationToken);
#else
            return this.HttpClient.SendAsync(request, cancellationToken).GetAwaiter().GetResult();
#endif
        }
    }
}

I'm assuming it's always present but happy to make it nullable and make it conditional