lld: error: permission denied with Burst 1.5.6

Unity Engine
,
1

Following along with Unity’s new Netcode tutorial here: https://docs-multiplayer.unity3d.com/docs/migration/install , when I add the Netcode package it automatically installs Burst 1.5.6 which generates errors. Testing, I was able to reproduce by adding Burst without Netcode. In fact, simply opening up a new 3D project and adding Burst 1.5.6 package generates these errors.

The first error I get is:

lld: error: permission denied
F:\Unity\Netcodetest\Temp\Burst\burst-aotcz42wayp.x9w\71379079a2462591f55eabd5eeba5c69.pdb: Stream Error: An I/O error occurred on the file system.
While compiling job: System.Int32 Unity.Burst.Intrinsics.X86::smile:oGetCSRTrampoline()
at :line 0

This is followed by another 40+ errors, alternating between the one above and the one below (more or less)

Unexpected exception Burst.Compiler.IL.Aot.AotLinkerException: The native link step failed. Check previous exception in the log - linker command line : “F:\Unity\Netcodetest\Library\PackageCache\com.unity.burst@1.5.6.Runtime\hostwin\lld -flavor link “@F:\AppData\Local\Temp\tmp18ec4834.tmp””
at Burst.Compiler.IL.Aot.AotNativeLinkBase.RunNativeLinkerTool (System.String command, System.String arguments, System.String errorMessage, System.String commandType, System.String workingDirectory, System.Boolean muteOutputs) [0x000d0] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Aot.AotNativeLinkLLVMWindows.Link (Burst.Backend.TargetCpu targetCpu, System.Collections.Generic.List1[T] inputFiles, System.String outputFile, System.Boolean enableDebugInfo) [0x00192] in <838ad2b6e5304123afbe0023ba8e151b>:0* *at Burst.Compiler.IL.Aot.AotCompiler.Link (System.Collections.Generic.List1[T] groups, System.String nameSuffix, Burst.Compiler.IL.Aot.AotCompilerOptions compilerOptions, System.IO.TextWriter consoleOut, System.IO.TextWriter consoleError) [0x001f8] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Jit.Providers.BaseOnDiskProvider.CommonDiskCompileModule (Burst.Backend.Module module, Burst.Compiler.IL.NativeCompiler nativeCompiler, Burst.Compiler.IL.NativeCompilerOptions options, Burst.Compiler.IL.Jit.JitOptions jitOptions, Burst.Compiler.IL.Helpers.Hash128& moduleHash) [0x00089] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Jit.Providers.OnDiskJitProvider.BeginCompileModule (Burst.Backend.Module module, Burst.Compiler.IL.NativeCompiler nativeCompiler, Burst.Compiler.IL.NativeCompilerOptions options, Burst.Compiler.IL.Jit.JitOptions jitOptions, Burst.Compiler.IL.Helpers.Hash128& moduleHash, Burst.Compiler.IL.Jit.JitCacheManager jitCacheManager, Burst.Compiler.IL.Jit.GetExternalFunctionPointerDelegate getExternalFunctionPointer, System.Action& invokeBurstInitialize) [0x00000] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Jit.JitCompiler.CompileMethodInternal (Burst.Compiler.IL.Jit.JitResult result, System.Collections.Generic.List1[T] methodsToCompile, Burst.Compiler.IL.Jit.JitOptions jitOptions) [0x005d6] in <838ad2b6e5304123afbe0023ba8e151b>:0* *at Burst.Compiler.IL.Jit.JitCompiler.CompileMethods (System.ValueTuple2[Mono.Cecil.MethodReference,System.String][ ] methodReferences, Burst.Compiler.IL.Jit.JitOptions jitOptions) [0x002c1] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Jit.JitCompiler.CompileMethod (Mono.Cecil.MethodReference methodReference, System.String methodRefString, Burst.Compiler.IL.Jit.JitOptions jitOptions) [0x0002c] in <838ad2b6e5304123afbe0023ba8e151b>:0
at Burst.Compiler.IL.Jit.JitCompilerService+CompilerThreadContext.Compile (Burst.Compiler.IL.Jit.JitCompilerService+CompileJob job) [0x00464] in <838ad2b6e5304123afbe0023ba8e151b>:0
While compiling job: System.Int32 Unity.Burst.Intrinsics.X86::smile:oGetCSRTrampoline()
at :line 0

I’ve tried deleting temp files in both the project folder, C:\Users.…\AppData\Local\Temp, and the F:\Users.…\AppData\Local\Temp. I’m not even sure what to try next.

2

Hi, sorry to hear you’ve been having these issues. This sounds like the same problem as here: After updating the project, errors appeared

When I follow those steps, I’m not able to reproduce this bug on my computer. Do you get it reliably every time you open the project?

My only idea so far is that might be related to some other process, such as an anti-virus program, holding a lock on that file. Do you have anti-virus software running? If so it may be worth adding an exclusion for your project folder and see if the issue still happens.