Path.GetTempFileName() sometimes fails on WASM due to insufficient randomness

[radical]

Build, seen on multiple PRs with no related changes. Which suggests that this is on main. Failures like:

[19:23:32] info: Starting:    System.CodeDom.Tests.dll
[19:23:39] fail: [FAIL] System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(source: "")
[19:23:39] info: System.IO.IOException : File exists
[19:23:39] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:23:39] info:    at Interop.ThrowIOExceptionForLastError()
[19:23:39] info:    at System.IO.Directory.CreateTempSubdirectoryCore(String prefix)
[19:23:39] info:    at System.IO.Directory.CreateTempSubdirectory(String prefix)
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.GetTempDirectory()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.EnsureTempNameCreated()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.get_BasePath()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.AddExtension(String fileExtension, Boolean keepFile)
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.AddExtension(String fileExtension)
[19:23:39] info:    at System.CodeDom.Compiler.CodeCompiler.FromSourceBatch(CompilerParameters options, String[] sources)
[19:23:39] info:    at System.CodeDom.Compiler.CodeCompiler.FromSource(CompilerParameters options, String source)
[19:23:39] info:    at System.CodeDom.Compiler.Tests.CodeCompilerTests.Compiler.FromSourceEntryPoint(CompilerParameters options, String source)
[19:23:39] info:    at System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(String source)
[19:23:39] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)

.. and ..

[19:27:13] info: Starting:    System.Diagnostics.TextWriterTraceListener.Tests.dll
[19:27:14] fail: [FAIL] System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "")
[19:27:14] info: System.IO.IOException : File exists
[19:27:14] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(Int64 result, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(IntPtr result, String path, Boolean isDirectory)
[19:27:14] info:    at System.IO.Path.GetTempFileName()
[19:27:14] info:    at System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(String testName)
[19:27:14] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)
[19:27:14] fail: [FAIL] System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "><&")
[19:27:14] info: System.IO.IOException : File exists
[19:27:14] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(Int64 result, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(IntPtr result, String path, Boolean isDirectory)
[19:27:14] info:    at System.IO.Path.GetTempFileName()
[19:27:14] info:    at System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(String testName)
[19:27:14] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)

Just for people reading this in the future, the list of failed tests:

System.CodeDom.Compiler.Tests.CodeCompilerTests.FromDom_ValidCodeCompileUnit_ReturnsExpected(compilationUnit: CodeCompileUnit { AssemblyCustomAttributes = [], EndDirectives = [], Namespaces = [], ReferencedAssemblies = ["assembly1", "assembly2"], StartDirectives = [], ... })
System.CodeDom.Compiler.Tests.CodeCompilerTests.GetResponseFileCmdArgs_ValidCmdArgs_ReturnsExpected(cmdArgs: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.CompileAssemblyFromSourceBatch_ValidSources_ReturnsExpected(sources: [null])
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(source: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSourceBatch_ValidSources_ReturnsExpected(sources: [""])
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ThrowsPlatformNotSupportedException(source: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromDom_ValidCodeCompileUnit_ThrowsPlatformNotSupportedException(compilationUnit: CodeCompileUnit { AssemblyCustomAttributes = [], EndDirectives = [], Namespaces = [], ReferencedAssemblies = ["referenced", "assembly1"], StartDirectives = [], ... })
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSourceBatch_ValidSources_ThrowsPlatformNotSupportedException(sources: [""])

System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"...)
System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "><&")
System.Diagnostics.TextWriterTraceListenerTests.XmlWriterTraceListenerTests.SingleArgumentConstructorTest

 ystem.ServiceModel.Syndication.Tests.BasicScenarioTests.SyndicationFeed_Write_RSS_Atom

The full set can be seen with that build url. I think #73408 broke these tests.

@eerhardt

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Issue Details

---

Build, seen on multiple PRs with no related changes. Which suggests that this is on main. Failures like:

[19:23:32] info: Starting:    System.CodeDom.Tests.dll
[19:23:39] fail: [FAIL] System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(source: "")
[19:23:39] info: System.IO.IOException : File exists
[19:23:39] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:23:39] info:    at Interop.ThrowIOExceptionForLastError()
[19:23:39] info:    at System.IO.Directory.CreateTempSubdirectoryCore(String prefix)
[19:23:39] info:    at System.IO.Directory.CreateTempSubdirectory(String prefix)
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.GetTempDirectory()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.EnsureTempNameCreated()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.get_BasePath()
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.AddExtension(String fileExtension, Boolean keepFile)
[19:23:39] info:    at System.CodeDom.Compiler.TempFileCollection.AddExtension(String fileExtension)
[19:23:39] info:    at System.CodeDom.Compiler.CodeCompiler.FromSourceBatch(CompilerParameters options, String[] sources)
[19:23:39] info:    at System.CodeDom.Compiler.CodeCompiler.FromSource(CompilerParameters options, String source)
[19:23:39] info:    at System.CodeDom.Compiler.Tests.CodeCompilerTests.Compiler.FromSourceEntryPoint(CompilerParameters options, String source)
[19:23:39] info:    at System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(String source)
[19:23:39] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)

.. and ..

[19:27:13] info: Starting:    System.Diagnostics.TextWriterTraceListener.Tests.dll
[19:27:14] fail: [FAIL] System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "")
[19:27:14] info: System.IO.IOException : File exists
[19:27:14] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(Int64 result, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(IntPtr result, String path, Boolean isDirectory)
[19:27:14] info:    at System.IO.Path.GetTempFileName()
[19:27:14] info:    at System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(String testName)
[19:27:14] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)
[19:27:14] fail: [FAIL] System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "><&")
[19:27:14] info: System.IO.IOException : File exists
[19:27:14] info:    at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(Int64 result, String path, Boolean isDirectory)
[19:27:14] info:    at Interop.CheckIo(IntPtr result, String path, Boolean isDirectory)
[19:27:14] info:    at System.IO.Path.GetTempFileName()
[19:27:14] info:    at System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(String testName)
[19:27:14] info:    at System.Reflection.MethodInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)

Just for people reading this in the future, the list of failed tests:

System.CodeDom.Compiler.Tests.CodeCompilerTests.FromDom_ValidCodeCompileUnit_ReturnsExpected(compilationUnit: CodeCompileUnit { AssemblyCustomAttributes = [], EndDirectives = [], Namespaces = [], ReferencedAssemblies = ["assembly1", "assembly2"], StartDirectives = [], ... })
System.CodeDom.Compiler.Tests.CodeCompilerTests.GetResponseFileCmdArgs_ValidCmdArgs_ReturnsExpected(cmdArgs: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.CompileAssemblyFromSourceBatch_ValidSources_ReturnsExpected(sources: [null])
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ReturnsExpected(source: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSourceBatch_ValidSources_ReturnsExpected(sources: [""])
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ThrowsPlatformNotSupportedException(source: "")
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromDom_ValidCodeCompileUnit_ThrowsPlatformNotSupportedException(compilationUnit: CodeCompileUnit { AssemblyCustomAttributes = [], EndDirectives = [], Namespaces = [], ReferencedAssemblies = ["referenced", "assembly1"], StartDirectives = [], ... })
System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSourceBatch_ValidSources_ThrowsPlatformNotSupportedException(sources: [""])

System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"...)
System.Diagnostics.TextWriterTraceListenerTests.CtorsDelimiterTests.TestConstructorWithFileNameAndName(testName: "><&")
System.Diagnostics.TextWriterTraceListenerTests.XmlWriterTraceListenerTests.SingleArgumentConstructorTest

 ystem.ServiceModel.Syndication.Tests.BasicScenarioTests.SyndicationFeed_Write_RSS_Atom

The full set can be seen with that build url. I think #73408 broke these tests.

@eerhardt

Author:	radical
Assignees:	-
Labels:	arch-wasm, area-System.IO, os-windows, blocking-clean-ci, test-failure
Milestone:	-

[eerhardt]

I can't repro this locally. Is it possible the machine's TEMP directories are full?

[radical]

I will try to repro this too. Locally, and on CI.

[radical]

I tried debugging this on helix with #73743 .

With the exception, I also printed the list of files, and directories in the temp path, before and after the mkdtemp call.
Log:

[06:39:10] fail: [FAIL] System.CodeDom.Compiler.Tests.CodeCompilerTests.FromSource_ValidSource_ThrowsPlatformNotSupportedException(source: "")
[06:39:10] info: Assert.Throws() Failure
[06:39:10] info: Expected: typeof(System.PlatformNotSupportedException)
[06:39:10] info: Actual:   typeof(System.Exception): io: System.IO.IOException: File exists
[06:39:10] info:              at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory)
[06:39:10] info:              at Interop.ThrowIOExceptionForLastError()
[06:39:10] info:              at System.IO.Directory.CreateTempSubdirectoryCore(String prefix) (hresult: 20 $
[06:39:10] info:           debug: Tries to create /tmp/XXXXXX in /tmp/
[06:39:10] info:           before: files:
[06:39:10] info:           before: directories: /tmp/iBahFK,/tmp/OLKNPB,/tmp/GnFpaC
[06:39:10] info:           after: files:
[06:39:10] info:           after: directories: /tmp/iBahFK,/tmp/OLKNPB,/tmp/GnFpaC

• One thing to note here is that it was expecting a PNSE, so the native function shouldn't have been called at all?
• Another, is that it says File exists, but the hresult from the error is 20 ( at System.IO.Directory.CreateTempSubdirectoryCore(String prefix) (hresult: 20) - which corresponds to ENODIR, IIUC.
  • so that looks like at least one issue
• I think ENODIR here means that some part of the /tmp/ path doesn't exist? But I'm not sure what to make of it
• As can be seen, the list of dirs is the same before, and after the call
• And if you look farther in the log, for other tests, and you can see that there were other directories created too in /tmp

I'm not sure what exactly might be going on. Maybe somebody familiar with node/windows can help.

cc @pavelsavara @maraf

[danmoseley]

Also note that CreateTempSubdirectoryCore ought to be passing the path to ThrowExceptionForIoErrno so that it appears in the error message.