Build errors after cleaning bin/obj

[davidortinau]

Android framework version

net9.0-android

Affected platform version

VS Code, .NET 10 P3, TFM is net9.0-android

Description

I see other reports of some of these errors like #9321

I can repeat this pretty reliably by deleting the bin/obj and hitting F5 from VS Code on macOS.

You are using a preview version of .NET. See: https://aka.ms/dotnet-support-policy
 Telepathic net9.0-android failed with 1 error(s) (4.3s)
 /usr/local/share/dotnet/packs/Microsoft.Android.Sdk.Darwin/35.0.61/tools/Xamarin.Android.EmbeddedResource.targets(39,5): 

error XARLP7000: Xamarin.Tools.Zip.ZipException: Renaming temporary file failed: No such file or directory
at Xamarin.Tools.Zip.ZipArchive.Close() in /Users/runner/work/1/s/LibZipSharp/Xamarin.Tools.Zip/ZipArchive.cs:line 991
at Xamarin.Android.Tasks.ZipArchiveEx.Dispose(Boolean disposing) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Utilities/ZipArchiveEx.cs:line 232
at Xamarin.Android.Tasks.ZipArchiveEx.Dispose() in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Utilities/ZipArchiveEx.cs:line 225
at Xamarin.Android.Tasks.ResolveLibraryProjectImports.<>c__DisplayClass81_0.<CreateResourceArchive>b__0(String f) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs:line 514
at Xamarin.Android.Tasks.ResolveLibraryProjectImports.<>c__DisplayClass81_0.<CreateResourceArchive>b__0(String f) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs:line 512
at Microsoft.Android.Build.Tasks.Files.ArchiveZipUpdate(String target, Action`1 archiver) in /Users/runner/work/1/s/xamarin-android/external/xamarin-android-tools/src/Microsoft.Android.Build.BaseTasks/Files.cs:line 137
at Xamarin.Android.Tasks.ResolveLibraryProjectImports.CreateResourceArchive(String resDir, String outputFile) in/Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs:line 511
at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(IDictionary`2 jars, ICollection`1 resolvedResourceDirectories, ICollection`1 resolvedAssetDirectories, ICollection`1 resolvedEnvironments, ICollection`1 proguardConfigFiles, ICollection`1 extractedDirectories) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs:line 479
at Xamarin.Android.Tasks.ResolveLibraryProjectImports.RunTask() in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs:line 106
at Microsoft.Android.Build.Tasks.AndroidTask.Execute() in /Users/runner/work/1/s/xamarin-android/external/xamarin-android-tools/src/Microsoft.Android.Build.BaseTasks/AndroidTask.cs:line 25

Build failed with 1 error(s) in 4.4s

 * The terminal process "/bin/zsh '-l', '-c', 'dotnet build -t:Run -p:Configuration=Debug -f net9.0-android -p:AdbTarget=-s%20emulator-5554 -p:AndroidAttachDebugger=true -p:AndroidSdbTargetPort=63536 -p:AndroidSdbHostPort=63536 -p:CustomAfterMicrosoftCSharpTargets="/Users/davidortinau/.vscode-insiders/extensions/ms-dotnettools.dotnet-maui-1.10.16-darwin-arm64/dist/resources/Custom.After.Microsoft.CSharp.targets" -p:MauiVSCodeBuildOutputFile="/var/folders/qn/w9562c_n0kq36zc8lqtg_yzh0000gn/T/dotnet-maui/maui-vsc-d138a987-169d-4ffe-8c49-96ba42e03f68.json" -p:AndroidSdkDirectory="/Users/davidortinau/Library/Android/sdk" -p:JavaSdkDirectory="/Library/Java/JavaVirtualMachines/microsoft-21.jdk/Contents/Home" -p:XamlTools="/Users/davidortinau/.vscode-insiders/extensions/ms-dotnettools.csharp-2.74.24-darwin-arm64/.xamlTools" /Users/davidortinau/work/dotnet-buildai/src/Telepathic/Telepathic.csproj'" terminated with exit code: 1. 
 * Terminal will be reused by tasks, press any key to close it. 

Build for iOS. Delete Bin/Obj. Build for Android.

Telepathic net9.0-android failed with 1 error(s) (1.2s)
 /usr/local/share/dotnet/packs/Microsoft.Android.Sdk.Darwin/35.0.61/tools/Xamarin.Android.Common.targets(2661,2): error XARDF7024: 
 System.IO.IOException: Directory not empty : '/Users/davidortinau/work/dotnet-buildai/src/Telepathic/obj/Debug/net9
 .0-android/lp/147/jl'
 at System.IO.FileSystem.RemoveDirectoryRecursive(String fullPath)
 at Xamarin.Android.Tasks.RemoveDirFixed.RunTask() in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.
 Build.Tasks/Tasks/RemoveDirFixed.cs:line 66

Build failed with 1 error(s) in 1.4s

 * The terminal process "/bin/zsh '-l', '-c', 'dotnet build -t:Run -p:Configuration=Debug -f net9.0-android -p:AdbTarget=-s%20emulator-5554 -p:AndroidAttachDebugger=true -p:AndroidSdbTargetPort=50024 -p:AndroidSdbHostPort=50024 -p:CustomAfterMicrosoftCSharpTargets="/Users/davidortinau/.vscode-insiders/extensions/ms-dotnettools.dotnet-maui-1.10.16-darwin-arm64/dist/resources/Custom.After.Microsoft.CSharp.targets" -p:MauiVSCodeBuildOutputFile="/var/folders/qn/w9562c_n0kq36zc8lqtg_yzh0000gn/T/dotnet-maui/maui-vsc-0a92e09d-b2f0-4d57-be62-06ccab4a452f.json" -p:AndroidSdkDirectory="/Users/davidortinau/Library/Android/sdk" -p:JavaSdkDirectory="/Library/Java/JavaVirtualMachines/microsoft-21.jdk/Contents/Home" -p:XamlTools="/Users/davidortinau/.vscode-insiders/extensions/ms-dotnettools.csharp-2.74.24-darwin-arm64/.xamlTools" /Users/davidortinau/work/dotnet-buildai/src/Telepathic/Telepathic.csproj'" terminated with exit code: 1. 
 * Terminal will be reused by tasks, press any key to close it. 

I'm also on macOS 15.4.1, M4 Max

Steps to Reproduce

Some combo of:

Build for a non-Android platform
Clean bin/obj
Build for Android
Observe some error
F5 again without changing anything and succeed.

Did you find any workaround?

No response

Relevant log output

[jonathanpeppers]

Can you get a .binlog? Once it fails like that try a command-line build:

dotnet build -t:Run -f net9.0-android -bl

And share the .binlog here.

It probably doesn't matter if you have .NET 10, the build tasks for TargetFramework=net9.0-android would use our stable packages.

[SuperJMN]

Confirming I'm hitting this on Linux (CLI, no IDE involved) with .NET 10.0.201 + Android SDK 36.1.53 (TFM net10.0-android). Same XARDF7024 / RemoveDirFixed / Directory not empty, intermittent, simply re-running dotnet publish succeeds.

Repro

It reproduces reliably (~30–50% of runs) under the following conditions:

1. Repo lives on an NTFS volume mounted with the kernel ntfs3 driver on Linux (/dev/sdX on /mnt/... type ntfs3 (rw,relatime,uid=1000,gid=1000,force,iocharset=utf8)).
2. Run dotnet publish -c Release -f net10.0-android -p:AndroidKeyStore=true ... from a tool / shell (not from VS / VS Code).
3. The failure points at obj/Release/net10.0-android/android/assets/<abi> (in my case arm64-v8a), exactly the path RemoveDirFixed is trying to delete.

Re-running dotnet publish immediately after the failure succeeds in nearly all cases. Manually rm -rf obj/Release/net10.0-android/android between the two attempts makes the second run succeed 100% of the time in my testing.

Likely amplifier: NTFS via ntfs3

I strongly suspect ntfs3 is amplifying an existing race rather than being the root cause. NTFS directory metadata updates aren't POSIX-equivalent: a directory can momentarily report children that have just been unlinked, which is exactly the failure mode RemoveDirectoryRecursive -> "Directory not empty" exhibits here. I have not been able to reproduce it on the same machine when the repo lives on an ext4 partition, only on the NTFS one — so this looks like a "scale-up" repro for whatever timing window already exists in RemoveDirFixed.

If a maintainer wants to repro on Linux without dual-booting Windows, mounting any NTFS partition with ntfs3 and dropping a small Android project on it should be enough to flush the bug out fairly quickly.

Stack trace (for the search engines)

error XARDF7024: System.IO.IOException: Directory not empty : '.../obj/Release/net10.0-android/android/assets/arm64-v8a'
 at System.IO.FileSystem.RemoveDirectoryRecursive(String fullPath)
 at Xamarin.Android.Tasks.RemoveDirFixed.RunTask()

Environment

• OS: Pop!_OS 24.04 LTS, kernel 6.18.7, x86_64
• .NET SDK: 10.0.201 (runtime 10.0.5), linux-x64
• Workload pack: Microsoft.Android.Sdk.Linux 36.1.53
• TFM: net10.0-android
• Filesystem: NTFS via kernel ntfs3 driver (mount line above)
• Invocation: programmatic dotnet publish from a CLI tool, single -m:1 not enforced

Workaround I've shipped in my deployment tool: detect XARDF7024 (or Directory not empty + RemoveDirFixed in the output), rm -rf obj/Release/<tfm>/android, and retry dotnet publish once. Unblocks our CI without any user-visible impact, but it's clearly a band-aid for an upstream race.

Happy to gather strace / inotify traces of a failing run if that would help triage.

[jonathanpeppers]

@SuperJMN can your AI open a PR to fix it? It sounds confident. 😄

I would be ok to make RemoveDirFixed just warn if it can't delete a folder.

[SuperJMN]

@SuperJMN can your AI open a PR to fix it? It sounds confident. 😄

I would be ok to make RemoveDirFixed just warn if it can't delete a folder.

Of course! Give me a minute ;D

[SuperJMN]

Update: PR up at #11195 — diagnosis turned out to be tiny and non-controversial.

TL;DR: RemoveDirFixed already retries with backoff, it just wasn't whitelisting ERROR_DIR_NOT_EMPTY (0x80070091), which is what .NET maps ENOTEMPTY from rmdir(2) to on Unix. Three lines: one new constant, one extra term in the existing if. No change in behavior once retries are exhausted.

Ball's in your court @jonathanpeppers — happy to add a test if you want one (didn't add one because the only honest deterministic repro needs an ntfs3 mount or a refactor to inject Directory.Delete, both of which felt heavy for a 3-line guardrail).