Copying assembly from directory Temp to Library/ScriptAssemblies failed

I'm trying to build the PC player on 2018.2.06b but the process quits because of this error, it doesn't go away when I hit "Clear" on the console and If I hit play the editor tells me: "All compiler errors have to be fixed before you can enter playmode!", just as if it was a compilation error and obviously it is not.

I could generate the PC build the first time, but the I realized I didn't update the scene list, so I added the missing scene to the build list and when I tried to "Build and Run" again I got this error. the Temp folder does not exist inside the project's folder. I had to delete the Library folder in order to recover from this, but it took a long while.

 

I've been having this same issue. Having to restart Unity each time and sometimes that does not fix the error. It happens whenever I add/edit a script and go back into Unity and immediately following the compiling process. (Unity Version : 2018.1.0f2)

 

If you can reproduce this problem, could you please submit a bug-report, as explained here:
https://unity3d.com/unity/qa/bug-reporting

Unity Technologies is probably not able to help you, or repair their software, if nobody with this problem shares the project with them.

 

This is moderately common when using the new Incremental Compiler. You guys using it? Forcing a recompilation a few times has, so far, always worked for me. A quick way to force it is to reimport an asmdef file. When it works, you can try creating the build again.

 

Yes, I am using the incremental compiler.

 

Case 1044452

 

I have this same issue in 2018.1.3f1.

 

same issue on 2018.1.of2

 

I did run many times into this one, not new to me. The problem is that "Random" exists in at least two namespaces, UnityEngine and System. If you use both namespaces in the same .cs file, the Compiler generates this error.

In order to fix the error, either clean up the "usings" or use a fully qualified name, such as UnityEngine.Random.Range() instead.

 

This happened to me on OSX having a project's root folder with an ' character on it's name, the incremental compiler created a new folder at the same level, with the same name but without the ', and only a Temp folder inside.

 

Always with the latest one, in my case. Currently 0.0.42-preview.7

 

Working with Unity 2018.2.0.b9 - Incremental Compiler v0.0.38

Error "Copying assembly from directory Temp to Library/ScriptAssemblies failed" appears randomly when creating (and possibly modifying - didn't test it but it seems probable) files in a project directory.
Can't send a bug report, as I can't reproduce the bug itself.

Creating a dummy file and then deleting it seems to remove the issue whenever it pops up.

Needs more investigating, though.

 

On it.

 

Still haven't got it (takes a while sometimes), but I did get one that might be interesting. I noticed that sometimes the compiler would just die forever and I would have to restart Unity. With my stress test now I found out what was going on. Here's the thread: Incremental Compiler dies because of OutOfMemoryException and never restarts

 

Got it. I removed (most of) the compiler warnings to make it easier to read.

Log: https://www.dropbox.com/s/d63doxx8t23kuei/Editor.Log_IncrementalCompiler_0.0.42-preview9.txt?dl=0

 

Here's the code if anyone wants to try stress testing on their side as well:
I just quickly extracted from the tool I use for this. It will randomly reimport an asmdef file until the error pops up.
It only works on projects that have asmdef files.

Note: the editor might stall forever in a "compiling" state because of the OutOfMemory exception that I mentioned a few posts back. In that case, restart the editor.

Also, there's probably a way to get the asmdef files that is better than literally iterating over all scripts. Sorry about that, this is quick and dirty.

Code (CSharp):

1. using System.Collections.Generic;
2. using UnityEditor;
3. using UnityEditor.Compilation;
4. using UnityEngine;
5.  
6. public static class CompilationStressTester {
7.  
8.     private const string K_STOP_FLAG = "StopMenuForceRecompileUntilErrorAppears";
9.  
10.  
11.     [MenuItem("Tools/Compilation/" + nameof(ResetCompilationStressTestFlags))]
12.     private static void ResetCompilationStressTestFlags() {
13.         EditorPrefs.SetBool(K_STOP_FLAG, false);
14.     }
15.  
16.  
17.     [MenuItem("Tools/Compilation/Force recompile UNTIL ASSEMBLY COPYING ERROR SHOWS UP")]
18.     [InitializeOnLoadMethod]
19.     private static void MenuForceRecompileUntilErrorAppears() {
20.         if (EditorPrefs.GetBool(K_STOP_FLAG)) {
21.             UnityEngine.Debug.Log("GOT ERROR. WILL NOT LOOP.");
22.             return;
23.         }
24.  
25.         UnityEngine.Debug.Log("LOOPING UNTIL THE ERROR SHOWS UP");
26.         UnityEngine.Application.logMessageReceived -= logMessageReceived;
27.         UnityEngine.Application.logMessageReceived += logMessageReceived;
28.         MenuForceRecompile();
29.     }
30.  
31.  
32.     private static bool TryGetCustomAssemblyForScript(string scriptPath, out string asmdefFilePath) {
33.         asmdefFilePath = CompilationPipeline.GetAssemblyDefinitionFilePathFromScriptPath(scriptPath);
34.         return !string.IsNullOrEmpty(asmdefFilePath);
35.     }
36.  
37.  
38.     private static void MenuForceRecompile() {
39.         var allScripts = MonoImporter.GetAllRuntimeMonoScripts();
40.         var asmdefFiles = new HashSet<string>();
41.         foreach (var monoScript in allScripts) {
42.             var scriptPath = AssetDatabase.GetAssetPath(monoScript);
43.             if (TryGetCustomAssemblyForScript(scriptPath, out var asmdefFilePath)) {
44.                 asmdefFiles.Add(asmdefFilePath);
45.             }
46.         }
47.  
48.         if (asmdefFiles.Count == 0) {
49.             UnityEngine.Debug.LogWarning("Coult not find any amsdef files. Failed to force a recompilation!");
50.             return;
51.         }
52.  
53.         //randomly reimport one
54.         var toReimportIndex = UnityEngine.Random.Range(0, asmdefFiles.Count - 1);
55.         var asmdefFilePathToReimport = asmdefFiles.ToList()[toReimportIndex];
56.         UnityEngine.Debug.Log($"Reimporting {asmdefFilePathToReimport} to trigger a recompilation.");
57.         AssetDatabase.ImportAsset(asmdefFilePathToReimport, ImportAssetOptions.ForceSynchronousImport);
58.     }
59.  
60.  
61.     private static void logMessageReceived(string condition, string stackTrace, LogType type) {
62.         if (type == LogType.Error || (condition?.Contains("assembly") == true && condition?.Contains("failed") == true)) {
63.             UnityEngine.Application.logMessageReceived -= logMessageReceived;
64.             EditorPrefs.SetBool(K_STOP_FLAG, true);
65.             UnityEngine.Debug.Log("GOT ERROR. STOPPING LOG MONITORING.");
66.         }
67.     }
68.  
69. }