Hi Steven,

The commit
0e7e7a264cd80ab71ea0f9e9da2d0617d4b539c4
BaseTools: Improve the cache hit in the edk2 build cache
Author: Shi, Steven <steven.shi@intel.com>  2019-08-15 07:26:17
Committer: Feng, Bob C <bob.c.feng@intel.com>  2019-08-19 23:06:05
Parent: 811328172841ce3f7ec1fe7033c130726ad189b7 (ShellPkg/UefiShellDriver1CommandsLib: Make array big enough)
Child:  56c786b0a9fd4f08b1f0bc10b7718a7577cb0146 (BaseTools: Print first cache missing file for build cachle)
Branches: master, remotes/origin/master
Follows: edk2-stable201905
Precedes: edk2-stable201908

causes "unknown fatal error" in build.py when building our platform.

Here is the log:
...
build.py...
 : error C0DE: Unknown fatal error when processing [/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/ArmPkg/Library/ArmGicArchSecLib/ArmGicArchSecLib.inf]

(Please send email to devel@edk2.groups.io for help, attaching following call stack trace!)

(Python 3.6.8 on linux) Traceback (most recent call last):
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/BinWrappers/PosixLike/../../Source/Python/build/build.py", line 2493, in Main
    MyBuild.Launch()
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/BinWrappers/PosixLike/../../Source/Python/build/build.py", line 2287, in Launch
    self._BuildPlatform()
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/BinWrappers/PosixLike/../../Source/Python/build/build.py", line 1742, in _BuildPlatform
    self._BuildPa(self.Target, Pa, FfsCommand=CmdListDict,PcdMaList=PcdMaList)
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/BinWrappers/PosixLike/../../Source/Python/build/build.py", line 1236, in _BuildPa
    AutoGenObject.CreateCodeFile(True)
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/Source/Python/Common/caching.py", line 18, in CallMeHere
    Value = self._function(obj, *args,**kwargs)
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/Source/Python/AutoGen/PlatformAutoGen.py", line 171, in CreateCodeFile
    Ma.CreateCodeFile(CreateModuleCodeFile)
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py", line 1841, in CreateCodeFile
    LibraryAutoGen.CreateCodeFile()
  File "/home/volovyan/otherwork/sandbox/uefi-related/uefi-orig/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py", line 1886, in CreateCodeFile
    with GlobalData.cache_lock:
AttributeError: __enter__


- Failed -
Build end time: 13:31:30, Sep.06 2019
Build total time: 00:00:04

Builds before the above mentioned commit was pushed, were fine.

Thank you,
Vladimir