Enable parallelism in test projects

src/Particular.LicensingComponent.UnitTests/NUnitSettings.cs

@@ -0,0 +1,5 @@
+using NUnit.Framework;
+
+[assembly: FixtureLifeCycle(LifeCycle.InstancePerTestCase)]
+[assembly: Parallelizable(ParallelScope.All)]
+[assembly: LevelOfParallelism(4)]

src/ServiceControl.AcceptanceTests.RavenDB/NUnitSettings.cs

@@ -0,0 +1,5 @@
+using NUnit.Framework;
+
+[assembly: FixtureLifeCycle(LifeCycle.InstancePerTestCase)]
+[assembly: Parallelizable(ParallelScope.All)]
+[assembly: LevelOfParallelism(4)]

src/ServiceControl.AcceptanceTests.RavenDB/Recoverability/MessageFailures/When_a_failed_message_is_retried.cs

@@ -17,8 +17,13 @@
     using NUnit.Framework;
     using ServiceControl.MessageFailures;
     using ServiceControl.Recoverability;
-    using TestSupport;
 
+    /// <summary>
+    /// This test gets run first and serially, this is to allow the non-threadsafe onetime setup to
+    /// happen without lifting it into a setup fixture.
+    /// </summary>
+    [Order(1)]
+    [NonParallelizable]
     class When_a_failed_message_is_retried : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Monitoring/InternalCustomChecks/When_a_critical_error_is_triggered.cs

@@ -12,6 +12,7 @@
     using ServiceControl.Operations;
 
     [TestFixture]
+    [NonParallelizable]
     class When_a_critical_error_is_triggered : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/Cors/When_cors_allows_any_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.AcceptanceTests.Security.Cors
     /// When AllowAnyOrigin is true (default for backwards compatibility), requests from any origin should be allowed.
     /// The Access-Control-Allow-Origin header should be "*".
     /// </summary>
+    [NonParallelizable]
     class When_cors_allows_any_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Cors/When_cors_is_disabled.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.AcceptanceTests.Security.Cors
     /// When AllowAnyOrigin is false and no AllowedOrigins are configured, CORS is effectively disabled.
     /// No Access-Control-Allow-Origin header should be returned for any origin.
     /// </summary>
+    [NonParallelizable]
     class When_cors_is_disabled : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Cors/When_request_from_allowed_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.AcceptanceTests.Security.Cors
     /// When a request comes from an origin that is in the AllowedOrigins list,
     /// the response should include the Access-Control-Allow-Origin header with that specific origin.
     /// </summary>
+    [NonParallelizable]
     class When_request_from_allowed_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Cors/When_request_from_disallowed_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.AcceptanceTests.Security.Cors
     /// When a request comes from an origin that is NOT in the AllowedOrigins list,
     /// the response should NOT include an Access-Control-Allow-Origin header that matches the request origin.
     /// </summary>
+    [NonParallelizable]
     class When_request_from_disallowed_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_forwarded_headers_are_disabled.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Forwarded Headers Disabled
     /// When forwarded headers processing is disabled, headers should be ignored regardless of trust.
     /// </summary>
+    [NonParallelizable]
     class When_forwarded_headers_are_disabled : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_forwarded_headers_are_sent.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Default Behavior with Headers
     /// When forwarded headers are sent and TrustAllProxies is true (default), headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_forwarded_headers_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_known_networks_are_configured.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Known Networks (CIDR)
     /// When KnownNetworks are configured and the caller IP falls within, headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_known_networks_are_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_known_proxies_are_configured.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Known Proxies Only
     /// When KnownProxies are configured and the caller IP matches, headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_known_proxies_are_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_multiple_header_values_are_sent.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is true and headers contain multiple values (proxy chain),
     /// the original (leftmost) values should be returned.
     /// </summary>
+    [NonParallelizable]
     class When_multiple_header_values_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_multiple_header_values_are_sent_with_known_proxies.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies=false (known proxies configured), ForwardLimit=1,
     /// so only the rightmost values are processed.
     /// </summary>
+    [NonParallelizable]
     class When_multiple_header_values_are_sent_with_known_proxies : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_only_proto_header_is_sent.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Partial Headers (Proto Only)
     /// When only X-Forwarded-Proto is sent, only scheme should change.
     /// </summary>
+    [NonParallelizable]
     class When_only_proto_header_is_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_proxy_chain_headers_are_sent.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is true and X-Forwarded-For contains multiple IPs (proxy chain),
     /// the original client IP (first in the chain) should be returned.
     /// </summary>
+    [NonParallelizable]
     class When_proxy_chain_headers_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_proxy_chain_headers_are_sent_with_known_proxies.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Proxy Chain with Known Proxies (ForwardLimit=1)
     /// When TrustAllProxies=false (known proxies configured), ForwardLimit=1, so only the last proxy IP is processed.
     /// </summary>
+    [NonParallelizable]
     class When_proxy_chain_headers_are_sent_with_known_proxies : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_request_has_no_forwarded_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Direct Access (No Proxy)
     /// When no forwarded headers are sent, the request values should remain unchanged.
     /// </summary>
+    [NonParallelizable]
     class When_request_has_no_forwarded_headers : AcceptanceTest
     {
         [Test]

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_trust_all_proxies_is_explicitly_configured.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is explicitly configured via environment variable, headers should be applied.
     /// This test verifies the WithTrustAllProxies() configuration method works correctly.
     /// </summary>
+    [NonParallelizable]
     class When_trust_all_proxies_is_explicitly_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_unknown_network_sends_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Unknown Network Rejected
     /// When KnownNetworks are configured but the caller IP does NOT fall within, headers should be ignored.
     /// </summary>
+    [NonParallelizable]
     class When_unknown_network_sends_headers : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/ForwardedHeaders/When_unknown_proxy_sends_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.AcceptanceTests.Security.ForwardedHeaders
     /// Unknown Proxy Rejected
     /// When KnownProxies are configured but the caller IP does NOT match, headers should be ignored.
     /// </summary>
+    [NonParallelizable]
     class When_unknown_proxy_sends_headers : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Https/When_hsts_is_configured_in_development_mode.cs

@@ -13,6 +13,7 @@ namespace ServiceControl.AcceptanceTests.Security.Https
     /// In acceptance tests (which run in Development mode), HSTS headers are not sent.
     /// This test verifies that HSTS is correctly NOT applied in development mode.
     /// </summary>
+    [NonParallelizable]
     class When_hsts_is_configured_in_development_mode : AcceptanceTest
     {
         HttpsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Https/When_https_redirect_is_disabled.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.Https
     /// HTTPS Redirect Disabled (Default)
     /// When RedirectHttpToHttps is false (default), HTTP requests should not be redirected.
     /// </summary>
+    [NonParallelizable]
     class When_https_redirect_is_disabled : AcceptanceTest
     {
         HttpsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/Https/When_https_redirect_is_enabled.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.AcceptanceTests.Security.Https
     /// HTTPS Redirect Enabled
     /// When RedirectHttpToHttps is true, HTTP requests should be redirected to HTTPS.
     /// </summary>
+    [NonParallelizable]
     class When_https_redirect_is_enabled : AcceptanceTest
     {
         HttpsTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/OpenIdConnect/When_authentication_is_disabled.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.AcceptanceTests.Security.OpenIdConnect
     /// When Authentication.Enabled is false (default), all API endpoints should be accessible
     /// without authentication. Requests should not require Bearer tokens.
     /// </summary>
+    [NonParallelizable]
     class When_authentication_is_disabled : AcceptanceTest
     {
         OpenIdConnectTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/OpenIdConnect/When_authentication_is_enabled.cs

@@ -17,6 +17,7 @@ namespace ServiceControl.AcceptanceTests.Security.OpenIdConnect
     /// This test uses a mock OIDC server to provide discovery endpoints and signing keys,
     /// allowing full testing of the JWT Bearer authentication flow.
     /// </summary>
+    [NonParallelizable]
     class When_authentication_is_enabled : AcceptanceTest
     {
         OpenIdConnectTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/OpenIdConnect/When_my_routes_are_requested.cs

@@ -17,6 +17,7 @@ namespace ServiceControl.AcceptanceTests.Security.OpenIdConnect;
 /// It is the per-instance authorization contract ServicePulse consumes: it gates UI on routes it
 /// already calls rather than on the server's internal permission vocabulary.
 /// </summary>
+[NonParallelizable]
 class When_my_routes_are_requested : AcceptanceTest
 {
     OpenIdConnectTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/OpenIdConnect/When_service_pulse_authority_override_is_configured.cs

@@ -13,6 +13,7 @@ namespace ServiceControl.AcceptanceTests.Security.OpenIdConnect
     /// endpoint should return the overridden authority for ServicePulse to use instead of the
     /// main authority URL.
     /// </summary>
+    [NonParallelizable]
     class When_service_pulse_authority_override_is_configured : AcceptanceTest
     {
         OpenIdConnectTestConfiguration configuration;

src/ServiceControl.AcceptanceTests/Security/OpenIdConnect/When_service_pulse_offline_access_scope_is_disabled.cs

@@ -13,6 +13,7 @@ namespace ServiceControl.AcceptanceTests.Security.OpenIdConnect
     /// string returned by the authentication configuration endpoint should omit offline_access,
     /// so ServicePulse does not request a scope the identity provider disallows.
     /// </summary>
+    [NonParallelizable]
     class When_service_pulse_offline_access_scope_is_disabled : AcceptanceTest
     {
         OpenIdConnectTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests.RavenDB/ServiceControl.Audit.AcceptanceTests.RavenDB.csproj

@@ -27,6 +27,8 @@
     <Compile Include="..\ServiceControl.Audit.Persistence.Tests.RavenDB\SharedEmbeddedServer.cs" />
     <Compile Include="..\ServiceControl.Audit.Persistence.Tests.RavenDB\StopSharedDatabase.cs" />
     <Compile Remove="..\ServiceControl.Audit.AcceptanceTests\TestsFilter.cs" />
+    <Compile Remove="..\ServiceControl.Audit.AcceptanceTests\NUnitSettings.cs" />
+    <!-- NUnitSettings.cs is excluded because the embedded RavenDB server does not support concurrent database create/delete/index operations reliably -->
   </ItemGroup>
 
 </Project>

src/ServiceControl.Audit.AcceptanceTests/NUnitSettings.cs

@@ -0,0 +1,5 @@
+using NUnit.Framework;
+
+[assembly: FixtureLifeCycle(LifeCycle.InstancePerTestCase)]
+[assembly: Parallelizable(ParallelScope.All)]
+[assembly: LevelOfParallelism(4)]

src/ServiceControl.Audit.AcceptanceTests/Security/Cors/When_cors_allows_any_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.Cors
     /// When AllowAnyOrigin is true (default for backwards compatibility), requests from any origin should be allowed.
     /// The Access-Control-Allow-Origin header should be "*".
     /// </summary>
+    [NonParallelizable]
     class When_cors_allows_any_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/Cors/When_cors_is_disabled.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.Cors
     /// When AllowAnyOrigin is false and no AllowedOrigins are configured, CORS is effectively disabled.
     /// No Access-Control-Allow-Origin header should be returned for any origin.
     /// </summary>
+    [NonParallelizable]
     class When_cors_is_disabled : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/Cors/When_request_from_allowed_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.Cors
     /// When a request comes from an origin that is in the AllowedOrigins list,
     /// the response should include the Access-Control-Allow-Origin header with that specific origin.
     /// </summary>
+    [NonParallelizable]
     class When_request_from_allowed_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/Cors/When_request_from_disallowed_origin.cs

@@ -12,6 +12,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.Cors
     /// When a request comes from an origin that is NOT in the AllowedOrigins list,
     /// the response should NOT include an Access-Control-Allow-Origin header that matches the request origin.
     /// </summary>
+    [NonParallelizable]
     class When_request_from_disallowed_origin : AcceptanceTest
     {
         CorsTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_forwarded_headers_are_disabled.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Forwarded Headers Disabled
     /// When forwarded headers processing is disabled, headers should be ignored regardless of trust.
     /// </summary>
+    [NonParallelizable]
     class When_forwarded_headers_are_disabled : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_forwarded_headers_are_sent.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Default Behavior with Headers
     /// When forwarded headers are sent and TrustAllProxies is true (default), headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_forwarded_headers_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_known_networks_are_configured.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Known Networks (CIDR)
     /// When KnownNetworks are configured and the caller IP falls within, headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_known_networks_are_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_known_proxies_are_configured.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Known Proxies Only
     /// When KnownProxies are configured and the caller IP matches, headers should be applied.
     /// </summary>
+    [NonParallelizable]
     class When_known_proxies_are_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_multiple_header_values_are_sent.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is true and headers contain multiple values (proxy chain),
     /// the original (leftmost) values should be returned.
     /// </summary>
+    [NonParallelizable]
     class When_multiple_header_values_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_multiple_header_values_are_sent_with_known_proxies.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies=false (known proxies configured), ForwardLimit=1,
     /// so only the rightmost values are processed.
     /// </summary>
+    [NonParallelizable]
     class When_multiple_header_values_are_sent_with_known_proxies : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_only_proto_header_is_sent.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Partial Headers (Proto Only)
     /// When only X-Forwarded-Proto is sent, only scheme should change.
     /// </summary>
+    [NonParallelizable]
     class When_only_proto_header_is_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_proxy_chain_headers_are_sent.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is true and X-Forwarded-For contains multiple IPs (proxy chain),
     /// the original client IP (first in the chain) should be returned.
     /// </summary>
+    [NonParallelizable]
     class When_proxy_chain_headers_are_sent : AcceptanceTest
     {
         [Test]

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_proxy_chain_headers_are_sent_with_known_proxies.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Proxy Chain with Known Proxies (ForwardLimit=1)
     /// When TrustAllProxies=false (known proxies configured), ForwardLimit=1, so only the last proxy IP is processed.
     /// </summary>
+    [NonParallelizable]
     class When_proxy_chain_headers_are_sent_with_known_proxies : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_request_has_no_forwarded_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Direct Access (No Proxy)
     /// When no forwarded headers are sent, the request values should remain unchanged.
     /// </summary>
+    [NonParallelizable]
     class When_request_has_no_forwarded_headers : AcceptanceTest
     {
         [Test]

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_trust_all_proxies_is_explicitly_configured.cs

@@ -11,6 +11,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// When TrustAllProxies is explicitly configured via environment variable, headers should be applied.
     /// This test verifies the WithTrustAllProxies() configuration method works correctly.
     /// </summary>
+    [NonParallelizable]
     class When_trust_all_proxies_is_explicitly_configured : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_unknown_network_sends_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Unknown Network Rejected
     /// When KnownNetworks are configured but the caller IP does NOT fall within, headers should be ignored.
     /// </summary>
+    [NonParallelizable]
     class When_unknown_network_sends_headers : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/ForwardedHeaders/When_unknown_proxy_sends_headers.cs

@@ -10,6 +10,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.ForwardedHeaders
     /// Unknown Proxy Rejected
     /// When KnownProxies are configured but the caller IP does NOT match, headers should be ignored.
     /// </summary>
+    [NonParallelizable]
     class When_unknown_proxy_sends_headers : AcceptanceTest
     {
         ForwardedHeadersTestConfiguration configuration;

src/ServiceControl.Audit.AcceptanceTests/Security/Https/When_hsts_is_configured_in_development_mode.cs

@@ -13,6 +13,7 @@ namespace ServiceControl.Audit.AcceptanceTests.Security.Https
     /// In acceptance tests (which run in Development mode), HSTS headers are not sent.
     /// This test verifies that HSTS is correctly NOT applied in development mode.
     /// </summary>
+    [NonParallelizable]
     class When_hsts_is_configured_in_development_mode : AcceptanceTest
     {
         HttpsTestConfiguration configuration;