[PATCH 08/11] python: add 'make check-venv' invocation

[John Snow <jsnow@redhat.com>]

This is a *third* way to run the Python tests. Unlike the first two
(check-pipenv, check-tox), this version does not require any specific
interpreter version -- making it a lot easier to tell people to run it
as a quick smoketest prior to submission to GitLab CI.

Summary:

  Checked via GitLab CI:
    - check-pipenv: tests our oldest python & dependencies
    - check-tox: tests newest dependencies on all non-EOL python versions
  Executed only incidentally:
    - check-venv: tests newest dependencies on whichever python version

('make check' does not set up any environment at all, it just runs the
tests in your current environment. All four invocations perform the
exact same tests, just in different execution environments.)

Signed-off-by: John Snow <jsnow@redhat.com>
---
 python/Makefile | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/python/Makefile b/python/Makefile
index 5cb8378b81..76bb24e671 100644
--- a/python/Makefile
+++ b/python/Makefile
@@ -1,4 +1,6 @@
-.PHONY: help pipenv check-pipenv check clean distclean develop
+.PHONY: help pipenv venv check-venv check-pipenv check clean distclean develop
+
+QEMU_VENV_DIR=~/.cache/qemu-pyvenv
 
 help:
 	@echo "python packaging help:"
@@ -15,6 +17,11 @@ help:
 	@echo "    Requires: Python 3.6-3.10 and tox."
 	@echo "    Hint (Fedora): 'sudo dnf install python3-tox python3.10'"
 	@echo ""
+	@echo "make check-venv:"
+	@echo "    Run tests in a venv against your default python3 version."
+	@echo "    These tests use the newest dependencies."
+	@echo "    Requires: Python 3.x"
+	@echo ""
 	@echo "make develop:    Install deps for 'make check', and"
 	@echo "                 the qemu libs in editable/development mode."
 	@echo ""
@@ -23,6 +30,9 @@ help:
 	@echo "make pipenv"
 	@echo "    Creates pipenv's virtual environment (.venv)"
 	@echo ""
+	@echo "make venv"
+	@echo "    Creates a simple venv for check-venv. ($(QEMU_VENV_DIR))"
+	@echo ""
 	@echo "make clean:      remove package build output."
 	@echo ""
 	@echo "make distclean:  remove venv files, qemu package forwarder,"
@@ -37,8 +47,27 @@ pipenv: .venv
 check-pipenv: pipenv
 	@pipenv run make check
 
+venv: $(QEMU_VENV_DIR) $(QEMU_VENV_DIR)/bin/activate
+$(QEMU_VENV_DIR) $(QEMU_VENV_DIR)/bin/activate: setup.cfg
+	@echo "VENV $(QEMU_VENV_DIR)"
+	@python3 -m venv $(QEMU_VENV_DIR)
+	@(							\
+		echo "ACTIVATE $(QEMU_VENV_DIR)";		\
+		. $(QEMU_VENV_DIR)/bin/activate;		\
+		echo "INSTALL qemu[devel] $(QEMU_VENV_DIR)";	\
+		make develop 1>/dev/null;			\
+	)
+	@touch $(QEMU_VENV_DIR)
+
+check-venv: venv
+	@(							\
+		echo "ACTIVATE $(QEMU_VENV_DIR)";		\
+		. $(QEMU_VENV_DIR)/bin/activate;		\
+		make check;					\
+	)
+
 develop:
-	pip3 install -e .[devel]
+	pip3 install --disable-pip-version-check -e .[devel]
 
 check:
 	@avocado --config avocado.cfg run tests/
@@ -50,4 +79,4 @@ clean:
 	python3 setup.py clean --all
 
 distclean: clean
-	rm -rf qemu.egg-info/ .venv/ .tox/ dist/
+	rm -rf qemu.egg-info/ .venv/ .tox/ $(QEMU_VENV_DIR) dist/
-- 
2.31.1