The created files are on local drive. I saw the problem on the laptop
(XP-SP2), desktop(XP-SP3) and server (Win2003). But there's no such
problem on the Linux and Mac boxes.

I tried to use fopen/fwrite in my extension according to your
suggestion. The problem wasn't be reproduced. It seems the bug is more
alike in Python part.

My application is a build system and is also an open source project. Is
it possible for you to download it and try it in your box?

I created temporary user (py123, password: 123py123) for you (just in
case) and here's steps of how to reproduce it.

  1. Checkout the build system source code in, for example, c:\test
     C:\test> svn co --username py123 --password 123py123
https://buildtools.tianocore.org/svn/buildtools/trunk/BaseTools tools

  2. Checkout the source code to be built against in c:\test
     C:\test> svn co --username py123 --password 123py123
https://edk2.tianocore.org/svn/edk2/trunk/edk2 edk2

  3. Change the source code between line 222 and line 229 of
c:\test\tools\Source\Python\Common\Misc.py (SaveFileOnChange function)
like below:

     Fd = open(File, "wb")
     Fd.write(Content)
     Fd.flush()
     os.fsync(Fd.fileno())
     Fd.close()

  4. In c:\test\edk2, run
     C:\test\edk2> edksetup.bat
     C:\test\edk2> set PYTHONPATH=C:\test\tools\Source\Python
     C:\test\edk2> python.exe C:\test\tools\Source\Python\build\build.py
-n 2 -p MdeModulePkg\MdeModulePkg.dsc -a IA32 -s

  5. If the application stops with message like "makefile not found" or
"AutoGen.h not found" message, that means the problem happened.

Visual Studio 2005 is needed to reproduce it.