Announcement

Collapse
No announcement yet.

UnrealBuildTool Unable to open log file for writing because it is being used by another process

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    UnrealBuildTool Unable to open log file for writing because it is being used by another process

    I keep getting

    UnrealBuildTool : error : Unhandled exception: System.Exception: Unable to open log file for writing (UnrealEngine-dev-rendering\Engine\Programs\UnrealBuildTool\Log.txt) ---> System.IO.IOException: The process cannot access the file '\UnrealEngine-dev-rendering\Engine\Programs\UnrealBuildTool\Log.txt' because it is being used by another process.

    But there is no other process using it besides the build itself ??
    https://www.casualdistractiongames.com

    #2
    So I was able to get passed this by changing Maximum number of parallel project builds to 1 in Visual Studio (Menu> Tools > Options > Projects and solutions > Build and Run. )

    Of course this is not the fastest, but it seems to resolve error which I assume is caused by race condition and simultaneous building
    https://www.casualdistractiongames.com

    Comment


      #3
      I hit this too. IMO the log file should include the VS project name in its name so that it's unique.

      Disabling parallel builds allowed the real error to come through:

      Code:
      [245/2741] Module.ContentBrowser.2_of_3.cpp
      d:\epic games\source\dev-rendering\engine\source\editor\contentbrowser\private\sassetview.cpp(2031): fatal error C1001: An internal error has occurred in the compiler.
        (compiler file 'd:\agent\_work\1\s\src\vctools\compiler\utc\src\p2\main.c', line 187)
         To work around this problem, try simplifying or changing the program near the locations listed above.
        Please choose the Technical Support command on the Visual C++
         Help menu, or open the Technical Support help file for more information
          cl!InvokeCompilerPassW()+0x3e53c
          cl!InvokeCompilerPassW()+0x3d72c
          cl!InvokeCompilerPassW()+0x3c59f
          cl!InvokeCompilerPassW()+0x3b991
          cl!InvokeCompilerPassW()+0x12c3ae
          cl!InvokeCompilerPassW()+0x50db7
          cl!InvokeCompilerPassW()+0x50a2e
          cl!CloseTypeServerPDB()+0x494af
          cl!o_exp()+0x5a
          cl!BaseThreadInitThunk()+0x14
          cl!RtlUserThreadStart()+0x21
      The rest of them are basically the same thing.
      Last edited by Antidamage; 02-06-2019, 02:02 AM.

      Comment


        #4
        I'm also running into this when building the entire UE4 solution from the latest github sources master branch. Has anyone here reported the issue to Epic yet?
        Last edited by Doug_Richardson; 02-14-2019, 07:19 PM. Reason: typo

        Comment


          #5
          I found the answer and had a moment of deja vu. You need to turn parallel builds down to 1 in VS. You can possibly get away with more but most likely not.

          This will cause it to build slower, but it will actually work. Seems like a crazy thing to not have fixed in 22 versions of the engine though.

          Comment


            #6
            Oh, I had incorrectly skim read OptimisticMonkey's solution. When I read "Maximum number of parallel project builds" I stopped reading and assumed it was going to be setting MaxProcessorCount to 1 in BuildConfiguration.xml, which if was true would have pointed to a UE4 build bug. But this parallel build option in VS is a global setting, not per project. I didn't even know such an option existed.

            Although I can understand why this would mess up Unreal Build Tool, it would be nice if you got a warning about this (perhaps during VS project file generation), or if Epic said to set the value to 1 in the UE4 Visual Studio Setup Guide or github README. I'll try this solution out and if it works for me, I'll make a pull request on the README.

            Comment


              #7
              The weird thing is VS has nothing to do with the UE build, it just kicks off too many instances of UBT at once.

              Comment

              Working...
              X