An exception occurred: AttributeError module 'sys' has no attribute 'real_prefix'

[sunpub]

File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\util.py", line 1, in
# Copyright (c) Microsoft Corporation. All rights reserved.
^^^^^^^^^^^^^^^
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\util.py", line 16, in evaluate
return eval(expr, {}, sys.modules)
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\log.py", line 297, in
get_paths = lambda: util.evaluate(expr)
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\log.py", line 299, in report_paths
paths = get_paths()
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\log.py", line 328, in get_environment_description
report_paths("sys.real_prefix")
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\common\log.py", line 372, in describe_environment
info("{0}", get_environment_description(header))
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\server\api.py", line 56, in ensure_logging
log.describe_environment("Initial environment:")
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy\server\cli.py", line 492, in main
api.ensure_logging()
File "C:\Users\XXX.vscode\extensions\ms-python.debugpy-2025.18.0-win32-x64\bundled\libs\debugpy_main_.py", line 71, in
cli.main()
AttributeError: module 'sys' has no attribute 'real_prefix'

[rchiodo]

Something is changing 'eval' to not work. This code works fine for me. You can try sticking this in the file you're debugging and see what happens:

import os
import sys
import inspect

def force_str(s, encoding, errors="strict"):
    """Converts s to str, using the provided encoding. If s is already str,
    it is returned as is.
    """
    return s.decode(encoding, errors) if isinstance(s, bytes) else str(s)

def nameof(obj, quote=False):
    """Returns the most descriptive name of a Python module, class, or function,
    as a Unicode string

    If quote=True, name is quoted with repr().

    Best-effort, but guaranteed to not fail - always returns something.
    """

    try:
        name = obj.__qualname__
    except Exception:
        try:
            name = obj.__name__
        except Exception:
            # Fall back to raw repr(), and skip quoting.
            try:
                name = repr(obj)
            except Exception:
                return "<unknown>"
            else:
                quote = False

    if quote:
        try:
            name = repr(name)
        except Exception:
            pass

    return force_str(name, "utf-8", "replace")

def srcnameof(obj):
    """Returns the most descriptive name of a Python module, class, or function,
    including source information (filename and linenumber), if available.

    Best-effort, but guaranteed to not fail - always returns something.
    """

    name = nameof(obj, quote=True)

    # Get the source information if possible.
    try:
        src_file = inspect.getsourcefile(obj)
    except Exception:
        pass
    else:
        name += f" (file {src_file!r}"
        try:
            _, src_lineno = inspect.getsourcelines(obj)
        except Exception:
            pass
        else:
            name += f", line {src_lineno}"
        name += ")"

    return name

def evaluate(code, path=__file__, mode="eval"):
    # Setting file path here to avoid breaking here if users have set
    # "break on exception raised" setting. This code can potentially run
    # in user process and is indistinguishable if the path is not set.
    # We use the path internally to skip exception inside the debugger.
    expr = compile(code, path, "eval")
    return eval(expr, {}, sys.modules)

def swallow_exception(msg, *args, level="error", **kwargs):
    print(msg.format(*args, **kwargs))

def get_environment_description(header):
    import sysconfig
    import site  # noqa

    result = [header, "\n\n"]

    def report(s, *args, **kwargs):
        result.append(s.format(*args, **kwargs))

    def report_paths(get_paths, label=None):
        prefix = f"    {label or get_paths}: "

        expr = None
        if not callable(get_paths):
            expr = get_paths
            get_paths = lambda: evaluate(expr)
        try:
            paths = get_paths()
        except AttributeError:
            report("{0}<missing>\n", prefix)
            return
        except Exception:  # pragma: no cover
            swallow_exception(
                "Error evaluating {0}",
                repr(expr) if expr else srcnameof(get_paths),
                level="info",
            )
            return

        if not isinstance(paths, (list, tuple)):
            paths = [paths]

        for p in sorted(paths):
            report("{0}{1}", prefix, p)
            if p is not None:
                rp = os.path.realpath(p)
                if p != rp:
                    report("({0})", rp)
            report("\n")

            prefix = " " * len(prefix)

    report("System paths:\n")
    report_paths("sys.executable")
    report_paths("sys.prefix")
    report_paths("sys.base_prefix")
    report_paths("sys.real_prefix")
    report_paths("site.getsitepackages()")
    report_paths("site.getusersitepackages()")

    site_packages = [
        p
        for p in sys.path
        if os.path.exists(p) and os.path.basename(p) == "site-packages"
    ]
    report_paths(lambda: site_packages, "sys.path (site-packages)")

    for name in sysconfig.get_path_names():
        expr = "sysconfig.get_path({0!r})".format(name)
        report_paths(expr)

    report_paths("os.__file__")
    report_paths("threading.__file__")
    report_paths("debugpy.__file__")
    report("\n")

    importlib_metadata = None
    try:
        import importlib_metadata
    except ImportError:  # pragma: no cover
        try:
            from importlib import metadata as importlib_metadata
        except ImportError:
            pass
    if importlib_metadata is None:  # pragma: no cover
        report("Cannot enumerate installed packages - missing importlib_metadata.")
    else:
        report("Installed packages:\n")
        try:
            for pkg in importlib_metadata.distributions():
                report("    {0}=={1}\n", pkg.name, pkg.version)
        except Exception:  # pragma: no cover
            swallow_exception(
                "Error while enumerating installed packages.", level="info"
            )

    return "".join(result).rstrip("\n")

print(get_environment_description("Environment description:"))

That code is identical to what debugpy is running and I get no such exception. The eval is failing for you for some reason.