From 452d7da8801ca318f280bd1c1085c60b0b6f747f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Hrn=C4=8Diar?= Date: Sat, 23 Apr 2022 16:56:59 +0200 Subject: [PATCH] Fallback to pyproject.toml-based builds if setuptools cannot be imported (#10717) This fallback is only triggered if the project has a `setup.py` file. Co-authored-by: Tzu-ping Chung Co-authored-by: Pradyun Gedam --- news/10717.bugfix.rst | 1 + src/pip/_internal/cli/cmdoptions.py | 7 +++++++ src/pip/_internal/pyproject.py | 11 +++++++++-- 3 files changed, 17 insertions(+), 2 deletions(-) create mode 100644 news/10717.bugfix.rst diff --git a/news/10717.bugfix.rst b/news/10717.bugfix.rst new file mode 100644 index 00000000000..950a4521763 --- /dev/null +++ b/news/10717.bugfix.rst @@ -0,0 +1 @@ +Fallback to pyproject.toml-based builds if ``setup.py`` is present in a project, but ``setuptools`` cannot be imported. diff --git a/src/pip/_internal/cli/cmdoptions.py b/src/pip/_internal/cli/cmdoptions.py index cd1e8a00f63..91b94e3028c 100644 --- a/src/pip/_internal/cli/cmdoptions.py +++ b/src/pip/_internal/cli/cmdoptions.py @@ -10,6 +10,7 @@ # The following comment should be removed at some point in the future. # mypy: strict-optional=False +import importlib.util import logging import os import textwrap @@ -770,6 +771,12 @@ def _handle_no_use_pep517( """ raise_option_error(parser, option=option, msg=msg) + # If user doesn't wish to use pep517, we check if setuptools is installed + # and raise error if it is not. + if not importlib.util.find_spec("setuptools"): + msg = "It is not possible to use --no-use-pep517 without setuptools installed." + raise_option_error(parser, option=option, msg=msg) + # Otherwise, --no-use-pep517 was passed via the command-line. parser.values.use_pep517 = False diff --git a/src/pip/_internal/pyproject.py b/src/pip/_internal/pyproject.py index e183eaf8658..1e9119f3e5c 100644 --- a/src/pip/_internal/pyproject.py +++ b/src/pip/_internal/pyproject.py @@ -1,3 +1,4 @@ +import importlib.util import os from collections import namedtuple from typing import Any, List, Optional @@ -89,9 +90,15 @@ def load_pyproject_toml( # If we haven't worked out whether to use PEP 517 yet, # and the user hasn't explicitly stated a preference, - # we do so if the project has a pyproject.toml file. + # we do so if the project has a pyproject.toml file + # or if we cannot import setuptools. + + # We fallback to PEP 517 when without setuptools, + # so setuptools can be installed as a default build backend. + # For more info see: + # https://discuss.python.org/t/pip-without-setuptools-could-the-experience-be-improved/11810/9 elif use_pep517 is None: - use_pep517 = has_pyproject + use_pep517 = has_pyproject or not importlib.util.find_spec("setuptools") # At this point, we know whether we're going to use PEP 517. assert use_pep517 is not None