# Port Status — CPython 3.11.16 to Windows 98 SE

Date: 2026-08-17
Baseline: CPython `v3.11.16`
Compiler: MSVC 6.0 (`cl.exe` 12.00.8804), from external `MSVC600`
Host test environment: Linux + Wine

## Verified

- CPython source checkout is at the requested `v3.11.16` baseline.
- The MSVC600 tool bundle is present locally and its `VC98/bin/VCVARS32.BAT`
  environment script runs under Wine.
- MSVC6 reports:

  ```text
  Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 12.00.8804 for 80x86
  ```

- A direct compile probe reaches CPython 3.11 headers. The first unmodified
  probe fails before linking, proving the compiler is being invoked against the
  intended baseline.
- A project-local compatibility `inttypes.h` has been added under
  `compat/msvc600/` as the first isolated shim. It is not yet wired into
  CPython source or declared sufficient for the port.

## Current first-blocker evidence

The probe command was equivalent to:

```text
cl /nologo /I compat/msvc600 /I cpython/Include /I cpython/PC \
   /c cpython/Programs/python.c
```

The next errors include:

- `Py_uintptr_t` / `Py_intptr_t` configuration failures in `Include/pyport.h`
- unsupported C `inline` syntax in `Include/object.h` and other public headers
- unsupported `__declspec(deprecated)` annotations
- additional C99/C99-era declarations and compatibility assumptions

The compatibility header now supplies the pointer-sized typedefs required by
`pyport.h`; the current first compiler diagnostics after applying the saved
`compat/msvc600/cpython-3.11.16-vc6-headers.patch` are VC6's inability to parse
`long long` declarations in `Include/longobject.h` and C99-style integer
literal suffixes in `Include/pythread.h`. The shim and patch resolve only the
missing-header, pointer-type, inline, and deprecation layers; they are
intentionally not presented as a complete fix.

## Larger blockers to plan for

1. **Build-system mismatch:** CPython 3.11's Windows build expects Visual Studio
   2017-era MSBuild/vcxproj tooling. VC6 cannot consume the build as-is. A
   dedicated minimal VC6 makefile/project set is required.
2. **Compiler language gap:** CPython 3.11 source and headers use C99-era and
   later MSVC features that VC6 does not implement. Compatibility macros and
   carefully scoped source backports are required.
3. **Win9x API gap:** CPython 3.11's Windows layer assumes NT-family Unicode,
   synchronization, process, filesystem, and networking APIs. Windows 98 has
   no wide-character file APIs and lacks multiple newer kernel APIs.
4. **Runtime/library gap:** SSL, SQLite, ctypes, multiprocessing, asyncio,
   Unicode filesystem behavior, and parts of subprocess will need explicit
   feature gates or Win9x-specific implementations.
5. **Validation gap:** final success requires booting the built executable on
   Windows 98 SE; Wine compilation alone is not proof of Win9x runtime
   compatibility.

## Recommended next implementation slice

Do not attempt the complete CPython solution yet. First create a minimal VC6
build target for `pythoncore` plus `Programs/python.c`, then make the public
headers compile under VC6 through a clearly isolated compatibility layer. Keep
all changes small and testable. After the core links, address the Win9x API
surface one subsystem at a time.

## Scope boundary

This project does not vendor the 223 MB MSVC600 bundle into a distributable
repository. It records the external tool as a local build prerequisite. No
Microsoft compiler binaries or runtime files should be committed or published.