pypa/pip · error · ValueError

path '%s' cannot end with '/'

Error message

path '%s' cannot end with '/'

What it means

Raised by convert_path() on non-Unix-like systems when the pathname ends with '/'. A trailing separator would collapse to an empty final segment after splitting on '/', which is ambiguous for native path joining, so a ValueError is raised. Like the absolute-path check, it only triggers when os.sep != '/'.

Source

Thrown at src/pip/_vendor/distlib/util.py:476

def convert_path(pathname):
    """Return 'pathname' as a name that will work on the native filesystem.

    The path is split on '/' and put back together again using the current
    directory separator.  Needed because filenames in the setup script are
    always supplied in Unix style, and have to be converted to the local
    convention before we can actually use them in the filesystem.  Raises
    ValueError on non-Unix-ish systems if 'pathname' either starts or
    ends with a slash.
    """
    if os.sep == '/':
        return pathname
    if not pathname:
        return pathname
    if pathname[0] == '/':
        raise ValueError("path '%s' cannot be absolute" % pathname)
    if pathname[-1] == '/':
        raise ValueError("path '%s' cannot end with '/'" % pathname)

    paths = pathname.split('/')
    while os.curdir in paths:
        paths.remove(os.curdir)
    if not paths:
        return os.curdir
    return os.path.join(*paths)


class FileOperator(object):

    def __init__(self, dry_run=False):
        self.dry_run = dry_run
        self.ensured = set()
        self._init_record()

    def _init_record(self):
        self.record = False

View on GitHub (pinned to d7d0d0a394)

Solutions

1. Strip the trailing '/': convert_path('src/mypkg'.rstrip('/')).
2. Build paths with os.path.join and strip the separator before passing to convert_path.
3. Validate with 'if pathname.endswith("/"): pathname = pathname[:-1]'.

Example fix

// before
convert_path('src/mypkg/')  # on Windows
// after
convert_path('src/mypkg')

import os
def safe_convert_path(p):
    if os.sep != '/' and p.endswith('/'):
        p = p.rstrip('/')
    from distlib.util import convert_path
    return convert_path(p)

from distlib.util import convert_path
try:
    native = convert_path(p)
except ValueError as e:
    if 'cannot end with' in str(e):
        native = convert_path(p.rstrip('/'))
    else:
        raise

When it happens

Trigger: Calling convert_path('src/mypkg/') on Windows, or setup() receiving a directory-style path with a trailing slash on Windows.

Common situations: Path joining code that appends '/' unconditionally, or copy-pasted directory paths that retain their trailing separator.

Related errors

• path '%s' cannot be absolute
• Target path exists but is not a directory, will not continue
• {req_name} does not appear to be a Python project: neither '
• Directory {name!r} is not installable. Neither 'setup.py' no
• file '%r' does not exist

AI-assisted analysis of pypa/pip@d7d0d0a394 (2026-08-04). Data as JSON: /data/errors/ebe56e225dba2514.json. Report an issue: GitHub.