Use python venv to run tests, coverage and building diagrams locally (#1132)

This change adds these make targets:

* `venv` to create a virtual environment in `.venv` to be used by make targets below
  * NOTE: The `dnf` module needs to be installed through the operating system but we make it available to the venv by passing `--system-site-packages`.
* `test` runs tests in the virtual environment created above
* `coverage` runs coverage and produces a text and HTML report in the virtual environment created above
* `update-requirements` this is a helper target to update `requirements.txt` when you change something in `requirements.txt.in`. This is also done in the venv created above.

Other changes:

* `requirements.txt` got `pytest` as a new dependency because we use it in some tests.
* `.coveragerc` was added to include configuration for which files to omit from coverage.
  * Without this, coverage would include `/usr` directories.
* `*_test.py` files will now be excluded from the coverage because we're not interested in them.

* `cffi` was bumped from `1.15.1` to `1.17.1` for it to work with Python 3.13

This should fix this error:

```
      building '_cffi_backend' extension
      creating build/temp.linux-x86_64-cpython-313/c
      gcc -fno-strict-overflow -Wsign-compare -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -fcf-protection -fexceptions -fcf-protection -fexceptions -fcf-protection -fexceptions -O3 -fPIC -DFFI_BUILDING=1 -DUSE__THREAD -DHAVE_SYNC_SYNCHRONIZE -I/home/kkleine/src/llvm-snapshots/.venv/include -I/usr/include/python3.13 -c c/_cffi_backend.c -o build/temp.linux-x86_64-cpython-313/c/_cffi_backend.o
      c/_cffi_backend.c: In function ‘b_do_dlopen’:
      c/_cffi_backend.c:4523:22: warning: ‘Py_FileSystemDefaultEncoding’ is deprecated [-Wdeprecated-declarations]
       4523 |                      Py_FileSystemDefaultEncoding, &filename_or_null, &flags))
            |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      In file included from /usr/include/python3.13/Python.h:99,
                       from c/_cffi_backend.c:2:
      /usr/include/python3.13/fileobject.h:22:46: note: declared here
         22 | Py_DEPRECATED(3.12) PyAPI_DATA(const char *) Py_FileSystemDefaultEncoding;
            |                                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      c/_cffi_backend.c: In function ‘_my_PyErr_WriteUnraisable’:
      c/_cffi_backend.c:6112:9: error: implicit declaration of function ‘_PyErr_WriteUnraisableMsg’; did you mean ‘PyErr_WriteUnraisable’? [-Wimplicit-function-declaration]
       6112 |         _PyErr_WriteUnraisableMsg(PyText_AS_UTF8(s), NULL);
            |         ^~~~~~~~~~~~~~~~~~~~~~~~~
            |         PyErr_WriteUnraisable
      error: command '/usr/bin/gcc' failed with exit code 1
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for cffi
Failed to build cffi
```

Author: kwk

.coveragerc

@@ -0,0 +1,13 @@
+[run]
+# See https://coverage.readthedocs.io/en/latest/config.html#run-omit
+omit =
+    # omit anything in a .local or .venv directory anywhere
+    */.local/*
+    */.venv/*
+    # omit everything in /usr
+    /usr/*
+    # Omit any test file
+    *_test.py
+
+# See https://coverage.readthedocs.io/en/latest/config.html#run-data-file
+data_file=.coverage

.gitignore

@@ -1,5 +1,10 @@
 buildroot/
 *.rpm
-.coverage
 .vscode
 __pycache__/
+# Ignore coverage
+.coverage*
+# Don't ignore coverage configuration
+!.coveragerc
+# Ignore virtual env
+.venv/

Makefile

@@ -1,16 +1,46 @@
+SHELL := /bin/bash
+
+temp_dir:=$(shell mktemp -d)
+
+venv: .venv/touchfile
+
+.venv/touchfile: requirements.txt
+	rpm -q python3-devel
+	python3 -m venv --system-site-packages --upgrade-deps .venv
+	. .venv/bin/activate \
+	&& pip install -r requirements.txt \
+	&& pip install --upgrade pip
+	touch .venv/touchfile
+
+.PHONY: update-requirements
+update-requirements: venv
+	. .venv/bin/activate \
+	&& pip install pip-tools \
+	&& pip install --upgrade pip \
+	&& pip-compile -o requirements.txt requirements.txt.in
+
 .PHONY: build-diagrams
-build-diagrams:
-	$(eval temp_dir:=$(shell mktemp -d))
+build-diagrams: venv
 	$(eval yyyymmdd:=$(shell date '+%Y%m%d'))
 	git show origin/gh-pages:build-stats-big-merge.csv > $(temp_dir)/build-stats-big-merge.csv
 	git show origin/gh-pages:build-stats-pgo.csv > $(temp_dir)/build-stats-pgo.csv
-	scripts/get-build-stats.py --copr-projectname "llvm-snapshots-big-merge-$(yyyymmdd)" | tee -a $(temp_dir)/build-stats-big-merge.csv
-	scripts/get-build-stats.py --copr-projectname "llvm-snapshots-pgo-$(yyyymmdd)" | tee -a $(temp_dir)/build-stats-pgo.csv
-	scripts/create-diagrams.py --datafile-big-merge $(temp_dir)/build-stats-big-merge.csv --datafile-pgo $(temp_dir)/build-stats-pgo.csv
+	. .venv/bin/activate \
+	&& scripts/get-build-stats.py --copr-projectname "llvm-snapshots-big-merge-$(yyyymmdd)" | tee -a $(temp_dir)/build-stats-big-merge.csv \
+	&& scripts/get-build-stats.py --copr-projectname "llvm-snapshots-pgo-$(yyyymmdd)" | tee -a $(temp_dir)/build-stats-pgo.csv \
+	&& scripts/create-diagrams.py --datafile-big-merge $(temp_dir)/build-stats-big-merge.csv --datafile-pgo $(temp_dir)/build-stats-pgo.csv
 	xdg-open index.html
 
-.PHONY: test-snapshot-manager
-test-snapshot-manager: ci-coverage
+.PHONY: test
+test: venv
+	. .venv/bin/activate && pytest
+
+.PHONY: coverage
+coverage: venv
+	. .venv/bin/activate \
+	&& coverage erase \
+	&& coverage run -m pytest \
+	&& coverage report --show-missing \
+	&& coverage html
 
 # CI recipes
 
@@ -19,7 +49,7 @@ ci-coverage:
 	# Ensure previous data won't interfere with the new execution.
 	coverage erase
 	coverage run -m pytest
-	coverage report -m
+	coverage report --show-missing
 
 .PHONY: ci-test
 ci-test:

requirements.txt

@@ -1,12 +1,12 @@
 #
-# This file is autogenerated by pip-compile with Python 3.11
+# This file is autogenerated by pip-compile with Python 3.13
 # by the following command:
 #
 #    pip-compile --output-file=requirements.txt requirements.txt.in
 #
 certifi==2024.7.4
     # via requests
-cffi==1.15.1
+cffi==1.17.1
     # via
     #   cryptography
     #   pynacl
@@ -50,6 +50,8 @@ humanize==4.9.0
     # via copr-cli
 idna==3.7
     # via requests
+iniconfig==2.0.0
+    # via pytest
 jinja2==3.1.5
     # via copr-cli
 koji==1.35.2
@@ -65,11 +67,15 @@ narwhals==1.24.1
 numpy==1.26.3
     # via pandas
 packaging==23.2
-    # via plotly
+    # via
+    #   plotly
+    #   pytest
 pandas==2.2.3
     # via -r requirements.txt.in
 plotly==6.0.0
     # via -r requirements.txt.in
+pluggy==1.5.0
+    # via pytest
 pycparser==2.21
     # via cffi
 pygithub==2.6.1
@@ -80,6 +86,8 @@ pyjwt[crypto]==2.6.0
     # via pygithub
 pynacl==1.5.0
     # via pygithub
+pytest==8.3.4
+    # via -r requirements.txt.in
 python-dateutil==2.8.2
     # via
     #   koji

requirements.txt.in

@@ -15,3 +15,4 @@ requests==2.32.3
 fnc
 coverage==7.6.12
 koji
+pytest==8.3.4