Python bootstrapper fails on Windows after recent windows update

[carpenterjc]

🐞 bug report

Affected Rule

Its the the bootstrapper.

Is this a regression?

No, I believe a windows update as exposed a previously unfound bug which was there for a while .

Description

I see a KeyError stack trace sometimes on windows when we try an run an executable.
Example exception KeyError: 'ProductType'
I have also seen a different key be unavailable: KeyError: 'ServicePackMajorVersion' just to show this seems to be random MSI keys being unavailable.

🔬 Minimal Reproduction

This is a non-determenistic bug which only started happening after we applied windows patches last week, and even then it will work perfectly most of the time.

🔥 Exception or Error

 Traceback (most recent call last):
    File "", line 206, in addpackage
    File "", line 1, in 
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\_main\tools\src\foo\_bah.venv\lib\python3.12\site-packages\_bazel_site_init.py", line 236, in 
      COVERAGE_SETUP = _setup_sys_path()
                       ^^^^^^^^^^^^^^^^^
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\_main\tools\src\foo\_bah.venv\lib\python3.12\site-packages\_bazel_site_init.py", line 160, in _setup_sys_path
      _maybe_add_path(abs_path)
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\_main\tools\src\foo\_bah.venv\lib\python3.12\site-packages\_bazel_site_init.py", line 139, in _maybe_add_path
      path = _get_windows_path_with_unc_prefix(path)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\_main\tools\src\foo\_bah.venv\lib\python3.12\site-packages\_bazel_site_init.py", line 100, in _get_windows_path_with_unc_prefix
      if platform.win32_ver()[1] >= "10.0.14393":
         ^^^^^^^^^^^^^^^^^^^^
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\rules_python++python+python_3_12_x86_64-pc-windows-msvc\Lib\platform.py", line 449, in win32_ver
      version, csd, ptype, is_client = _win32_ver(version, csd, ptype)
                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\rules_python++python+python_3_12_x86_64-pc-windows-msvc\Lib\platform.py", line 387, in _win32_ver
      (version, product_type, ptype, spmajor, spminor)  = _wmi_query(
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "d:\.bzl\root\x5haxcyn\execroot\_main\bazel-out\x64_windows-opt-exec-st-43a81393d292\bin\tools\src\foo\bah.exe.runfiles\rules_python++python+python_3_12_x86_64-pc-windows-msvc\Lib\platform.py", line 333, in 
      return (dict_data[k] for k in keys)
              ~~~~~~~~~^^^
  KeyError: 'ProductType'

The python code in question looks like this; from Lib/platform.py:

try:
    import _wmi
except ImportError:
    def _wmi_query(*keys):
        raise OSError("not supported")
else:
    def _wmi_query(table, *keys):
        table = {
            "OS": "Win32_OperatingSystem",
            "CPU": "Win32_Processor",
        }[table]
        data = _wmi.exec_query("SELECT {} FROM {}".format(
            ",".join(keys),
            table,
        )).split("\0")
        split_data = (i.partition("=") for i in data)
        dict_data = {i[0]: i[2] for i in split_data}
        return (dict_data[k] for k in keys)
 

That's basically saying that one of the passed-in keys is not in the WMI response.

The place which failed for me was this caller:

def _win32_ver(version, csd, ptype):
# Try using WMI first, as this is the canonical source of data
try:
(version, product_type, ptype, spmajor, spminor) = _wmi_query(
'OS',
'Version',
'ProductType',
'BuildType',
'ServicePackMajorVersion',
'ServicePackMinorVersion',
)

Interestingly there's an except OSError, but this isn't an OSError, it's a KeyError. So we just fail, instead of the fallback code:

    except OSError:
        pass
    # Fall back to a combination of sys.getwindowsversion and "ver"
    try:
        from sys import getwindowsversion
    except ImportError:
        return version, csd, ptype, True
    winver = getwindowsversion()
    is_client = (getattr(winver, 'product_type', 1) == 1)
    try:
        version = _syscmd_ver()[2]
        major, minor, build = map(int, version.split('.'))
    except ValueError:
        major, minor, build = winver.platform_version or winver[:3]
        version = '{0}.{1}.{2}'.format(major, minor, build)
 

🌍 Your Environment

Operating System:

  
Windows
  

Output of bazel version:

  
8.6.0
  

Rules_python version:

  
1.8.5
  

Anything else relevant?

I asked AI about what updates have happened last week: KB5083769 (Windows 11 cumulative OS update): High likelihood of possible WMI impact

• KB5083769 (Windows 11 cumulative OS update): High likelihood of possible WMI impact
  Reason: It is a full OS cumulative update (OS builds 26200.8246 / 26100.8246). Even without explicit WMI notes, cumulative OS updates can change WBEM/WMI-adjacent components and behavior.
• KB5088467 (Servicing Stack Update): Medium indirect likelihood
  Reason: SSU primarily affects update installation stack, not WMI runtime directly, but it changes servicing infrastructure and can influence system component state.
• KB5082417 (.NET Framework 3.5/4.8.1 cumulative update): Medium likelihood if your tooling uses managed WMI APIs
  Reason: This update affects .NET runtime/libraries. If your apps/scripts use System.Management or managed WMI consumers, behaviour can change indirectly.

[aignas]

Have you tried 2.0-rc3 to see if this is reproducible with the latest version?

[rickeylev]

I ran into this briefly somewhere else, but don't remember where. I wonder if we can just remove that logic entirely?