python: warn if Microsoft Visual C++ runtime libs are not found (#2920)

Signed-off-by: Jared Van Bortel <jared@nomic.ai>

gpt4all-bindings/python/CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [Unreleased]
+
+### Added
+- Warn on Windows if the Microsoft Visual C++ runtime libraries are not found ([#2920](https://github.com/nomic-ai/gpt4all/pull/2920))
+
 ## [2.8.2] - 2024-08-14
 
 ### Fixed
@@ -56,6 +61,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
   - Restore leading space removal logic that was incorrectly removed in [#2694](https://github.com/nomic-ai/gpt4all/pull/2694)
   - CUDA: Cherry-pick llama.cpp DMMV cols requirement fix that caused a crash with long conversations since [#2694](https://github.com/nomic-ai/gpt4all/pull/2694)
 
+[Unreleased]: https://github.com/nomic-ai/gpt4all/compare/python-v2.8.2...HEAD
 [2.8.2]: https://github.com/nomic-ai/gpt4all/compare/python-v2.8.1...python-v2.8.2
 [2.8.1]: https://github.com/nomic-ai/gpt4all/compare/python-v2.8.0...python-v2.8.1
 [2.8.0]: https://github.com/nomic-ai/gpt4all/compare/python-v2.7.0...python-v2.8.0

gpt4all-bindings/python/gpt4all/_pyllmodel.py

@@ -37,7 +37,20 @@
         raise RuntimeError(textwrap.dedent("""\
             Running GPT4All under Rosetta is not supported due to CPU feature requirements.
             Please install GPT4All in an environment that uses a native ARM64 Python interpreter.
-        """))
+        """).strip())
+
+# Check for C++ runtime libraries
+if platform.system() == "Windows":
+    try:
+        ctypes.CDLL("msvcp140.dll")
+        ctypes.CDLL("vcruntime140.dll")
+        ctypes.CDLL("vcruntime140_1.dll")
+    except OSError as e:
+        print(textwrap.dedent(f"""\
+            {e!r}
+            The Microsoft Visual C++ runtime libraries were not found. Please install them from
+            https://aka.ms/vs/17/release/vc_redist.x64.exe
+        """), file=sys.stderr)
 
 
 def _load_cuda(rtver: str, blasver: str) -> None:

gpt4all-bindings/python/setup.py

@@ -68,7 +68,7 @@ def get_long_description():
 
 setup(
     name=package_name,
-    version="2.8.2",
+    version="2.8.3.dev0",
     description="Python bindings for GPT4All",
     long_description=get_long_description(),
     long_description_content_type="text/markdown",