System.IO.FileSystem.Watcher.Tests crashing on MacCatalyst

[runfoapp]

Seems to be in FileSystemWatcher_Directory_Create_InNestedDirectory:

Test collection for System.IO.Tests.Directory_Create_Tests
2022-02-18 09:37:11.786663-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: 	[PASS] System.IO.Tests.Directory_Create_Tests.FileSystemWatcher_Directory_PathNotExists
2022-02-18 09:37:11.793323-0800  localhost fseventsd[81]: (libsystem_info.dylib) Created Activity ID: 0x234d6, Description: Resolve user group list
2022-02-18 09:37:11.805998-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: 
Unhandled Exception:
Xunit.Sdk.ContainsException: Assert.Contains() Failure
Not found: /var/folders/62/ftpn5pv523j8xsdw56s9jnp40000gs/T/Directory_Create_Tests_hsm4w3hg.os4/FileSystemWatcher_Directory_Create_InNestedDirectory_53_bb03705a/dir1
In value:  String[] ["/var/folders/62/ftpn5pv523j8xsdw56s9jnp40000gs/T/D"...]
   at Xunit.Assert.Contains[String](String expected, IEnumerable`1 collection, IEqualityComparer`1 comparer) in /_/src/xunit.assert/Asserts/CollectionAsserts.cs:line 245
   at Xunit.Assert.Contains[String](String expected, IEnumerable`1 collection) in /_/src/xunit.assert/Asserts/CollectionAsserts.cs:line 226
   at System.IO.Tests.FileSystemWatcherTest.<>c__DisplayClass9_0.<WatchCreated>b__0(Object o, FileSystemEventArgs e)
   at System.IO.FileSystemWatcher.InvokeOn(FileSystemEventArgs e, FileSystemEventHandler handler)
   at System.IO.FileSystemWatcher.NotifyFileSystemEventArgs(WatcherChangeTypes changeType, ReadOnlySpan`1 name)
   at System.IO.FileSystemWatcher.RunningInstance.Process<…>
2022-02-18 09:37:11.806440-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: (CoreAnalytics) [com.apple.CoreAnalytics:client] Entering exit handler.
2022-02-18 09:37:11.806442-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: (CoreAnalytics) [com.apple.CoreAnalytics:client] Exiting exit handler.

Runfo Tracking Issue: System.IO.FileSystem.Watcher.Tests crashing on MacCatalyst

Build	Definition	Kind	Run Name	Console	Core Dump	Test Results	Run Client
1713622	runtime-extra-platforms	PR 67861	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1100.Arm64.Open	console.log			runclient.py
1711428	runtime-extra-platforms	PR 67861	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1100.Arm64.Open	console.log			runclient.py

Build Result Summary

Day Hit Count	Week Hit Count	Month Hit Count
0	2	2

Tagging subscribers to this area: @dotnet/area-system-io
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Runfo Creating Tracking Issue (data being generated)

Author:	runfoapp[bot]
Assignees:	-
Labels:	area-System.IO, untriaged
Milestone:	-

Tagging subscribers to 'os-maccatalyst': @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Test collection for System.IO.Tests.Directory_Create_Tests
2022-02-18 09:37:11.786663-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: 	[PASS] System.IO.Tests.Directory_Create_Tests.FileSystemWatcher_Directory_PathNotExists
2022-02-18 09:37:11.793323-0800  localhost fseventsd[81]: (libsystem_info.dylib) Created Activity ID: 0x234d6, Description: Resolve user group list
2022-02-18 09:37:11.805998-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: 
Unhandled Exception:
Xunit.Sdk.ContainsException: Assert.Contains() Failure
Not found: /var/folders/62/ftpn5pv523j8xsdw56s9jnp40000gs/T/Directory_Create_Tests_hsm4w3hg.os4/FileSystemWatcher_Directory_Create_InNestedDirectory_53_bb03705a/dir1
In value:  String[] ["/var/folders/62/ftpn5pv523j8xsdw56s9jnp40000gs/T/D"...]
   at Xunit.Assert.Contains[String](String expected, IEnumerable`1 collection, IEqualityComparer`1 comparer) in /_/src/xunit.assert/Asserts/CollectionAsserts.cs:line 245
   at Xunit.Assert.Contains[String](String expected, IEnumerable`1 collection) in /_/src/xunit.assert/Asserts/CollectionAsserts.cs:line 226
   at System.IO.Tests.FileSystemWatcherTest.<>c__DisplayClass9_0.<WatchCreated>b__0(Object o, FileSystemEventArgs e)
   at System.IO.FileSystemWatcher.InvokeOn(FileSystemEventArgs e, FileSystemEventHandler handler)
   at System.IO.FileSystemWatcher.NotifyFileSystemEventArgs(WatcherChangeTypes changeType, ReadOnlySpan`1 name)
   at System.IO.FileSystemWatcher.RunningInstance.Process<…>
2022-02-18 09:37:11.806440-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: (CoreAnalytics) [com.apple.CoreAnalytics:client] Entering exit handler.
2022-02-18 09:37:11.806442-0800  localhost System.IO.FileSystem.Watcher.Tests[3577]: (CoreAnalytics) [com.apple.CoreAnalytics:client] Exiting exit handler.

Runfo Tracking Issue: System.IO.FileSystem.Watcher.Tests crashing on MacCatalyst

Build	Definition	Kind	Run Name	Console	Core Dump	Test Results	Run Client
1621547	runtime-extra-platforms	Rolling	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1100.Arm64.Open	console.log			runclient.py
1620950	runtime-extra-platforms	PR 65551	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1100.Arm64.Open	console.log			runclient.py
1620484	runtime-extra-platforms	PR 65506	net7.0-MacCatalyst-Release-arm64-Mono_Release-OSX.1100.Arm64.Open	console.log			runclient.py

Build Result Summary

Day Hit Count	Week Hit Count	Month Hit Count
3	3	3

Author:	runfoapp[bot]
Assignees:	-
Labels:	area-System.IO, untriaged, runtime-mono, os-maccatalyst
Milestone:	-

[adamsitnik]

It can be related to #64906, but since it was very defensive change I expect it to expose an existing problem rather than introduce a new one.

@tmds when working on #64906 (and #57139) have you tried to figure out why the directory was getting removed in the meantime? I wonder if we have a test bug somewhere (deleting the directories before the tests finishes).

[tmds]

have you tried to figure out why the directory was getting removed in the meantime? I wonder if we have a test bug somewhere (deleting the directories before the tests finishes).

The ContentRoot of that test is /tmp so it observes removal of directories from other tests.

runtime/src/libraries/Microsoft.Extensions.Hosting/tests/UnitTests/HostTests.cs

Lines 195 to 207 in 87ab863

	var appSettingsPath = Path.Combine(Path.GetTempPath(), "appsettings.json");
	string SaveRandomConfig()
	{
	var newMessage = $"Hello ASP.NET Core: {Guid.NewGuid():N}";
	File.WriteAllText(appSettingsPath, $"{{ \"Hello\": \"{newMessage}\" }}");
	return newMessage;
	}
	var dynamicConfigMessage1 = SaveRandomConfig();
	using var host = Host.CreateDefaultBuilder()
	.UseContentRoot(Path.GetDirectoryName(appSettingsPath))

[adamsitnik]

The ContentRoot of that test is /tmp so it observes removal of directories from other tests.

So the long term fix would be to ensure that each test is using it's own directory?

[tmds]

So the long term fix would be to ensure that each test is using it's own directory?

Yes, tests are supposed to have their own directories so they work independent.
In this particular case, not following the pattern uncovered a bug in FileSystemWatcher.Linux.