WebGL build error on Arch linux

Hello,

While building for WebGL, unity Gives me 3 errors:

Error 1:
Exception: Unity.IL2CPP.Building.BuilderFailedException: /home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten_FastComp_Linux/clang++: error while loading shared libraries: libtinfo.so.5: cannot open shared object file: No such file or directory
/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/emcc.py:781: SyntaxWarning: “is not” with a literal. Did you mean “!=”?
newargs = [arg for arg in newargs if arg is not ‘’]
/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/emcc.py:896: SyntaxWarning: “is not” with a literal. Did you mean “!=”?
newargs = [a for a in newargs if a is not ‘’]
/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/emcc.py:1157: SyntaxWarning: “is not” with a literal. Did you mean “!=”?
assert options.use_closure_compiler is not 2, ‘EMTERPRETIFY requires valid asm.js, and is incompatible with closure 2 which disables that’
/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/emcc.py:2360: SyntaxWarning: “is not” with a literal. Did you mean “!=”?
newargs = [arg for arg in newargs if arg is not ‘’]
ERROR:root:compiler frontend failed to generate LLVM bitcode, halting

Invocation was: Executable: /usr/bin/python
Arguments: -E "/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/em++" -Wno-unused-value -Wno-invalid-offsetof -nostdinc -fno-strict-overflow -Wno-null-conversion -std=c++11 -O3 -Oz -DIL2CPP_EXCEPTION_DISABLED=1  -DNET_4_0 -DUNITY_AOT -DIL2CPP_MONO_DEBUGGER_DISABLED -DGC_NOT_DLL -DRUNTIME_IL2CPP -DBASELIB_INLINE_NAMESPACE=il2cpp_baselib -DNDEBUG -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/libil2cpp" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/libil2cpp" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/external/bdwgc/include" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/external/xxHash" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/external/baselib/Include" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/external/baselib/Platforms/WebGL/Include" -I"/home/viskyboi/Desktop/Unity/Unity Editor/2020.3.11f1/Editor/Data/il2cpp/libil2cpp/pch" -I"/home/viskyboi/Mod the Cube/Library/Il2cppBuildCache/WebGL/il2cppOutput" "/home/viskyboi/Mod the Cube/Library/Il2cppBuildCache/WebGL/il2cppOutput/Il2CppCCalculateFieldValues.cpp" -o "/home/viskyboi/Mod the Cube/Library/il2cpp_cache/65941F9C9CC49654962AD22E4ADA8300.o"

   at Unity.IL2CPP.Building.CppProgramBuilder.BuildAllCppFiles(IEnumerable`1 sourceFilesToCompile, IBuildStatisticsCollector statisticsCollector) in /Users/bokken/build/output/unity/il2cpp/Unity.IL2CPP.Building/CppProgramBuilder.cs:line 217
   at Unity.IL2CPP.Building.CppProgramBuilder.Build(IBuildStatistics& statistics) in /Users/bokken/build/output/unity/il2cpp/Unity.IL2CPP.Building/CppProgramBuilder.cs:line 149
   at il2cpp.Compilation.CompilationDriver.Run(RuntimePlatform platform, BuildingOptions buildingOptions, ReadOnlyCollection`1 matchedAssemblyMethodSourceFiles) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Compilation/CompilationDriver.cs:line 65
   at il2cpp.Program.DoRun(String[] args, RuntimePlatform platform, BuildingOptions buildingOptions, Boolean throwExceptions) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Program.cs:line 74
UnityEditorInternal.Runner.RunProgram (UnityEditor.Utils.Program p, System.String exe, System.String args, System.String workingDirectory, UnityEditor.Scripting.Compilers.CompilerOutputParserBase parser) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:129)
UnityEditorInternal.Runner.RunManagedProgram (System.String exe, System.String args, System.String workingDirectory, UnityEditor.Scripting.Compilers.CompilerOutputParserBase parser, System.Action`1[T] setupStartInfo) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:65)
UnityEditorInternal.IL2CPPBuilder.RunIl2CppWithArguments (System.Collections.Generic.List`1[T] arguments, System.Action`1[T] setupStartInfo) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:804)
UnityEditorInternal.IL2CPPBuilder.ConvertPlayerDlltoCpp (UnityEditor.Il2Cpp.Il2CppBuildPipelineData data) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:773)
UnityEditorInternal.IL2CPPBuilder.Run () (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:599)
UnityEditorInternal.IL2CPPUtils.RunIl2Cpp (System.String stagingAreaData, UnityEditorInternal.IIl2CppPlatformProvider platformProvider, System.Action`1[T] modifyOutputBeforeCompile, UnityEditor.RuntimeClassRegistry runtimeClassRegistry) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:276)
UnityEditor.WebGL.WebGlBuildPostprocessor.CompileBuild (UnityEditor.Modules.BuildPostProcessArgs args) (at /Users/bokken/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:365)
UnityEditor.WebGL.WebGlBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args) (at /Users/bokken/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:913)
UnityEditor.Modules.DefaultBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args, UnityEditor.BuildProperties& outProperties) (at /home/bokken/buildslave/unity/build/Editor/Mono/Modules/DefaultBuildPostprocessor.cs:29)
UnityEditor.PostprocessBuildPlayer.Postprocess (UnityEditor.BuildTargetGroup targetGroup, UnityEditor.BuildTarget target, System.String installPath, System.String companyName, System.String productName, System.Int32 width, System.Int32 height, UnityEditor.BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.Build.Reporting.BuildReport report) (at /home/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:337)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&) (at /home/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:189)

Error 2:

    Build completed with a result of 'Failed' in 132 seconds (131982 ms)
    UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&) (at /home/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:189)

Error 3:

    UnityEditor.BuildPlayerWindow+BuildMethodException: 2 errors
      at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x002be] in /home/bokken/buildslave/unity/build/Editor/Mono/BuildPlayerWindowBuildMethods.cs:190 
      at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in /home/bokken/buildslave/unity/build/Editor/Mono/BuildPlayerWindowBuildMethods.cs:95 
    UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&) (at /home/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:189)

I’m using Arch Linux

I am having the same problem. It is due to being on the latest version of Python most likely. My error reads kind of like SyntaxWarning: “is not” with a literal. Did you mean “!=”?
newargs = [arg for arg in newargs if arg is not ‘’]

Try installing ncurses5-compat-libs from AUR

In my case I upgraded to Unity 2021 and the build was successful