This is a workaround intended for Debian 10, where the debian-patched
pip does not function correctly if accessed from within a virtual
environment.
We don't support Debian 10 any longer, but it's possible that this bug
might appear on other derivative platforms and this workaround may prove
useful.
RFC, a note from Paolo:
"BTW, another way to repair Debian 10's pip is to create a symbolic link
to sys.base_prefix + '/share/python-wheels' in sys.prefix +
'/share/python-wheels'. Since this is much faster, perhaps it can be
done unconditionally [...] ?"
I was slightly apprehensive about this as it felt "hackier", but it is
indeed a lot less code and much faster. It's probably low-risk. Should
we do that instead, or should we just scrap any fix at all under the
premise that Debian 10 support is dropped anyway?
Signed-off-by: John Snow <js...@redhat.com>
---
python/scripts/mkvenv.py | 61 +++++++++++++++++++++++++++++-----------
1 file changed, 44 insertions(+), 17 deletions(-)
diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py
index 317697a953..6e1a979355 100644
--- a/python/scripts/mkvenv.py
+++ b/python/scripts/mkvenv.py
@@ -103,27 +103,25 @@ def need_ensurepip() -> bool:
return True
-def check_ensurepip(with_pip: bool) -> None:
+def check_ensurepip(prefix: str = '', suggest_remedy: bool = False) -> None:
"""
Check that we have ensurepip.
Raise a fatal exception with a helpful hint if it isn't available.
"""
- if not with_pip:
- return
-
if not find_spec("ensurepip"):
msg = ("Python's ensurepip module is not found.\n"
"It's normally part of the Python standard library, "
"maybe your distribution packages it separately?\n"
- "Either install ensurepip, or alleviate the need for it in the "
- "first place by installing pip and setuptools for "
- f"'{sys.executable}'.\n"
-
- "(Hint: Debian puts ensurepip in its python3-venv package.)")
- raise Ouch(msg)
+ "(Debian puts ensurepip in its python3-venv package.)\n")
+ if suggest_remedy:
+ msg += (
+ "Either install ensurepip, or alleviate the need for it in the
"
+ "first place by installing pip and setuptools for "
+ f"'{sys.executable}'.\n")
+ raise Ouch(prefix + msg)
# ensurepip uses pyexpat, which can also go missing on us:
if not find_spec("pyexpat"):
@@ -132,12 +130,13 @@ def check_ensurepip(with_pip: bool) -> None:
"It's normally part of the Python standard library, "
"maybe your distribution packages it separately?\n"
- "Either install pyexpat, or alleviate the need for it in the "
- "first place by installing pip and setuptools for "
- f"'{sys.executable}'.\n\n"
-
- "(Hint: NetBSD's pkgsrc debundles this to e.g. 'py310-expat'.)")
- raise Ouch(msg)
+ "(NetBSD's pkgsrc debundles this to e.g. 'py310-expat'.)\n")
+ if suggest_remedy:
+ msg += (
+ "Either install pyexpat, or alleviate the need for it in the "
+ "first place by installing pip and setuptools for "
+ f"'{sys.executable}'.\n")
+ raise Ouch(prefix + msg)
def make_venv( # pylint: disable=too-many-arguments
@@ -169,7 +168,8 @@ def make_venv( # pylint: disable=too-many-arguments
with_pip = True if not system_site_packages else need_ensurepip()
logger.debug("with_pip unset, choosing %s", with_pip)
- check_ensurepip(with_pip)
+ if with_pip:
+ check_ensurepip(suggest_remedy=True)
if symlinks is None:
# Default behavior of standard venv CLI
@@ -349,6 +349,31 @@ def _get_entry_points() -> Iterator[Dict[str, str]]:
logger.debug("wrote '%s'", script_path)
+def checkpip():
+ """
+ Debian10 has a pip that's broken when used inside of a virtual environment.
+
+ We try to detect and correct that case here.
+ """
+ try:
+ import pip._internal
+ logger.debug("pip appears to be working correctly.")
+ return
+ except ModuleNotFoundError as exc:
+ if exc.name == 'pip._internal':
+ # Uh, fair enough. They did say "internal".
+ # Let's just assume it's fine.
+ return
+ logger.warning("pip appears to be malfunctioning: %s", str(exc))
+
+ check_ensurepip("pip appears to be non-functional, and ")
+
+ logging.debug("Attempting to repair pip ...")
+ subprocess.run((sys.executable, '-m', 'ensurepip'),
+ stdout=subprocess.DEVNULL, check=True)
+ logging.debug("Pip is now (hopefully) repaired!")
+
+
def post_venv_setup(bin_path: str, packages: Sequence[str] = ()) -> None:
"""
This is intended to be run *inside the venv* after it is created.
@@ -358,6 +383,8 @@ def post_venv_setup(bin_path: str, packages: Sequence[str]
= ()) -> None:
bin_path, packages)
generate_console_scripts(python_path, bin_path, packages)
+ # Test for a broken pip (Debian 10 or derivative?) and fix it if needed
+ checkpip()
def main() -> int:
"""CLI interface to make_qemu_venv. See module docstring."""
--
2.39.2
