# Buggy code
def save(self, pypi_version, current_time):
    # Check to make sure that we own the directory
    if not check_path_owner(os.path.dirname(self.statefile_path)):
        return

    # Now that we've ensured the directory is owned by this user, we'll go
    # ahead and make sure that all our directories are created.
    ensure_dir(os.path.dirname(self.statefile_path))

    # Attempt to write out our version check file
    with lockfile.LockFile(self.statefile_path):
        if os.path.exists(self.statefile_path):
            with open(self.statefile_path) as statefile:
                state = json.load(statefile)
        else:
            state = {}

        state[sys.prefix] = {
            "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
            "pypi_version": pypi_version,
        }

        with open(self.statefile_path, "w") as statefile:
            json.dump(state, statefile, sort_keys=True, separators=(",", ":"))


# Traceback (TypeError)
pip install --no-cache-dir --verbose wheel
Config variable 'Py_DEBUG' is unset, Python ABI tag may be incorrect
Config variable 'WITH_PYMALLOC' is unset, Python ABI tag may be incorrect
Created temporary directory: C:\Users\User\AppData\Local\Temp\pip-ephem-wheel-cache-2e5wmnq3
Created temporary directory: C:\Users\User\AppData\Local\Temp\pip-req-tracker-gnigbooj
Created requirements tracker 'C:\\Users\\User\\AppData\\Local\\Temp\\pip-req-tracker-gnigbooj'
Created temporary directory: C:\Users\User\AppData\Local\Temp\pip-install-u77xlkpb
Requirement already satisfied: wheel in c:\users\user\prj\pip\venv\lib\site-packages (0.31.1)
Cleaning up...
Removed build tracker 'C:\\Users\\User\\AppData\\Local\\Temp\\pip-req-tracker-gnigbooj'
There was an error checking the latest version of pip
Traceback (most recent call last):
File "c:\users\user\prj\pip\src\pip\_internal\utils\outdated.py", line 90, in pip_version_check
state = SelfCheckState(cache_dir=options.cache_dir)
File "c:\users\user\prj\pip\src\pip\_internal\utils\outdated.py", line 25, in __init__
self.statefile_path = os.path.join(cache_dir, "selfcheck.json")
File "C:\Users\user\prj\pip\venv\lib\ntpath.py", line 76, in join
path = os.fspath(path)
TypeError: expected str, bytes or os.PathLike object, not bool

# Fixed code
def save(self, pypi_version, current_time):
    # If we do not have a path to cache in, don't bother saving.
    if not self.statefile_path:
        return

    # Check to make sure that we own the directory
    if not check_path_owner(os.path.dirname(self.statefile_path)):
        return

    # Now that we've ensured the directory is owned by this user, we'll go
    # ahead and make sure that all our directories are created.
    ensure_dir(os.path.dirname(self.statefile_path))

    # Attempt to write out our version check file
    with lockfile.LockFile(self.statefile_path):
        if os.path.exists(self.statefile_path):
            with open(self.statefile_path) as statefile:
                state = json.load(statefile)
        else:
            state = {}

        state[sys.prefix] = {
            "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
            "pypi_version": pypi_version,
        }

        with open(self.statefile_path, "w") as statefile:
            json.dump(state, statefile, sort_keys=True, separators=(",", ":"))