Do not fail on partial trust warning.

src/Aspire.Cli/Certificates/CertificateService.cs

@@ -42,6 +42,7 @@ public async Task EnsureCertificatesTrustedAsync(IDotNetCliRunner runner, Cancel
                 StandardOutputCallback = ensureCertificateCollector.AppendOutput,
                 StandardErrorCallback = ensureCertificateCollector.AppendError,
             };
+
             var trustExitCode = await interactionService.ShowStatusAsync(
                 ":locked_with_key: Trusting certificates...",
                 () => runner.TrustHttpCertificateAsync(
@@ -51,10 +52,12 @@ public async Task EnsureCertificatesTrustedAsync(IDotNetCliRunner runner, Cancel
             if (trustExitCode != 0)
             {
                 interactionService.DisplayLines(ensureCertificateCollector.GetLines());
-                throw new CertificateServiceException($"Failed to trust certificates, trust command failed with exit code: {trustExitCode}");
+                interactionService.DisplayMessage("warning", $"Developer certificates may not be fully trusted (trust exit code was: {trustExitCode})");
             }
         }
     }
+
+    internal const string DevCertsPartialTrustMessage = "There was an error trusting the HTTPS developer certificate. It will be trusted by some clients but not by others.";
 }
 
 public sealed class CertificateServiceException(string message) : Exception(message)

tests/Aspire.Cli.Tests/Certificates/CertificateServiceTests.cs

@@ -0,0 +1,40 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Aspire.Cli.Certificates;
+using Aspire.Cli.Tests.TestServices;
+using Aspire.Cli.Tests.Utils;
+using Microsoft.Extensions.DependencyInjection;
+using Xunit;
+
+namespace Aspire.Cli.Tests.Certificates;
+
+public class CertificateServiceTests(ITestOutputHelper outputHelper)
+{
+    [Fact]
+    public async Task EnsureCertificatesTrustedAsyncSucceedsOnNonZeroExitCode()
+    {
+        var services = CliTestHelper.CreateServiceCollection(outputHelper, options =>
+        {
+            options.DotNetCliRunnerFactory = sp =>
+            {
+                var runner = new TestDotNetCliRunner();
+                runner.CheckHttpCertificateAsyncCallback = (_, _) => 1;
+                runner.TrustHttpCertificateAsyncCallback = (options, _) =>
+                {
+                    Assert.NotNull(options.StandardErrorCallback);
+                    options.StandardErrorCallback!.Invoke(CertificateService.DevCertsPartialTrustMessage);
+                    return 4;
+                };
+                return runner;
+            };
+        });
+
+        var sp = services.BuildServiceProvider();
+        var cs = sp.GetRequiredService<ICertificateService>();
+        var runner = sp.GetRequiredService<IDotNetCliRunner>();
+
+        // If this does not throw then the code is behaving correctly.
+        await cs.EnsureCertificatesTrustedAsync(runner, TestContext.Current.CancellationToken).WaitAsync(CliTestConstants.DefaultTimeout);
+    }
+}