Open() on path that exceeds 248 char limit results in "FileNotFoundError: [Errno 2] No such file or directory"

Bug report

Attempting to open or appending paths to sys.path with paths that length exceed the 248 character limit results in incorrect errors. In the case of opening paths that exceeded the limit, rather than an error pointing to the path length being exceeded we see a file not found. A similar error handling issue is prevalent with appending paths that exceed the limit to sys.path. In this case when trying to access the module you will receive a module not found error. I am now aware the path limit can be disabled on installation or later but these false flags led me astray while debugging.

Reproduction Steps:

• Create a text file whose path exceeds 248 characters
• Attempt to read/write from that file
  or
• Create a Python module whose path exceeds 248 characters
• Attempt to import that module from an external directory by appending the path to sys.path

Environment

• CPython versions tested on: 3.10.4
• Operating system and architecture: Windows x64

Start by reproducing the reported behavior on Windows x64 with Python 3.10.4: open a file whose path exceeds 248 characters, then test importing a module from an overlong path appended to sys.path. Trace the open and import failures to identify where the length condition is lost. Done means both cases report an accurate path-length error instead of FileNotFoundError or ModuleNotFoundError.