Commit graph

15 commits

Author SHA1 Message Date
Paolo Bonzini 47a90a51a9 mkvenv: always pass locally-installed packages to pip
Let pip decide whether a new version should be installed or the current
one is okay.  This ensures that the virtual environment is updated
(either upgraded or downgraded) whenever a new version of a package is
requested.

The hardest part here is figuring out if a package is installed in
the venv (which also has to be done twice to account for the presence
of either setuptools in Python <3.8, or importlib in Python >=3.8).

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Cc: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-06-06 16:30:01 +02:00
Paolo Bonzini d37c21b5fb mkvenv: pass first missing package to diagnose()
If sphinx is present but the theme is not, mkvenv will print an
inaccurate diagnostic:

ERROR: Could not find a version that satisfies the requirement sphinx-rtd-theme>=0.5.0 (from versions: none)
ERROR: No matching distribution found for sphinx-rtd-theme>=0.5.0

'sphinx>=1.6.0' not found:
 • Python package 'sphinx' version '5.3.0' was found, but isn't suitable.
 • mkvenv was configured to operate offline and did not check PyPI.

Instead, ignore the packages that were found to be present, and report
an error based on the first absent package.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-19 20:40:29 +02:00
Paolo Bonzini c673f3d0fe mkvenv: replace distlib.database with importlib.metadata/pkg_resources
importlib.metadata is just as good as distlib.database and a bit more
battle-proven for "egg" based distributions, and in fact that is exactly
why mkvenv.py is not using distlib.database to find entry points: it
simply does not work for eggs.

The only disadvantage of importlib.metadata is that it is not available
by default before Python 3.8, so we need a fallback to pkg_resources
(again, just like for the case of finding entry points).  Do so to
fix issues where incorrect egg metadata results in a JSONDecodeError.

While at it, reuse the new _get_version function to diagnose an incorrect
version of the package even if importlib.metadata is not available.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-19 20:09:21 +02:00
Paolo Bonzini 3b087f79a4 meson: require 0.63.0
This version allows cleanups in modinfo collection, but they only
work with Ninja 1.9.x and 1.8.x is still supported.  It also supports the
equivalent of QEMU's --static option to configure.

The wheel file is bumped to 0.63.3, the last release in the 0.63 branch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
Paolo Bonzini 02312f1af1 mkvenv: mark command as required
This is only available in Python 3.7+.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-26-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow 2274817f6c python: add vendor.py utility
This is a teeny-tiny script that just downloads any packages we want to
vendor from PyPI and stores them in qemu.git/python/wheels/. If I'm hit
by a meteor, it'll be easy to replicate what I have done in order to
udpate the vendored source.

We don't really care which python runs it; it exists as a meta-utility
with no external dependencies and we won't package or install it. It
will be monitored by the linters/type checkers, though; so it's
guaranteed safe on python 3.6+.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-15-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow c804962617 mkvenv: work around broken pip installations on Debian 10
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 as a build platform any longer, though we do
still utilize it for our build-tricore-softmmu CI test. It's also
possible that this bug might appear on other derivative platforms and
this workaround may prove useful.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-11-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow f1ad527ff5 mkvenv: avoid ensurepip if pip is installed
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow 68ea6d17fe mkvenv: use pip's vendored distlib as a fallback
distlib is usually not installed on Linux distribution, but it is vendored
into pip.  Because the virtual environment has pip via ensurepip, we
can piggy-back on pip's vendored version.  This could break if they move
our cheese in the future, but the fix would be simply to require distlib.

If it is debundled, as it is on msys, it is simply available directly.

Signed-off-by: John Snow <jsnow@redhat.com>
[Move to toplevel. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow 928348949d mkvenv: add console script entry point generation
When creating a virtual environment that inherits system packages,
script entry points (like "meson", "sphinx-build", etc) are not
re-generated with the correct shebang. When you are *inside* of the
venv, this is not a problem, but if you are *outside* of it, you will
not have a script that engages the virtual environment appropriately.

Add a mechanism that generates new entry points for pre-existing
packages so that we can use these scripts to run "meson",
"sphinx-build", "pip", unambiguously inside the venv.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-9-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow 4695a22e9a mkvenv: add --diagnose option to explain "ensure" failures
This is a routine that is designed to print some usable info for human
beings back out to the terminal if/when "mkvenv ensure" fails to locate
or install a package during configure time, such as meson or sphinx.

Since we are requiring that "meson" and "sphinx" are installed to the
same Python environment as QEMU is configured to build with, this can
produce some surprising failures when things are mismatched. This method
is here to try and ease that sting by offering some actionable
diagnosis.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-8-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow c5538eed12 mkvenv: add ensure subcommand
This command is to be used to add various packages (or ensure they're
already present) into the configure-provided venv in a modular fashion.

Examples:

mkvenv ensure --online --dir "${source_dir}/python/wheels/" "meson>=0.61.5"
mkvenv ensure --online "sphinx>=1.6.0"
mkvenv ensure "qemu.qmp==0.0.2"

It's designed to look for packages in three places, in order:

(1) In system packages, if the version installed is already good
enough. This way your distribution-provided meson, sphinx, etc are
always used as first preference.

(2) In a vendored packages directory. Here I am suggesting
qemu.git/python/wheels/ as that directory. This is intended to serve as
a replacement for vendoring the meson source for QEMU tarballs. It is
also highly likely to be extremely useful for packaging the "qemu.qmp"
package in source distributions for platforms that do not yet package
qemu.qmp separately.

(3) Online, via PyPI, ***only when "--online" is passed***. This is only
ever used as a fallback if the first two sources do not have an
appropriate package that meets the requirement. The ability to build
QEMU and run tests *completely offline* is not impinged.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-7-jsnow@redhat.com>
[Use distlib to lookup distributions. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow dee01b827f mkvenv: add nested venv workaround
Python virtual environments do not typically nest; they may inherit from
the top-level system packages or not at all.

For our purposes, it would be convenient to emulate "nested" virtual
environments to allow callers of the configure script to install
specific versions of python utilities in order to test build system
features, utility version compatibility, etc.

While it is possible to install packages into the system environment
(say, by using the --user flag), it's nicer to install test packages
into a totally isolated environment instead.

As detailed in https://www.qemu.org/2023/03/24/python/, Emulate a nested
venv environment by using .pth files installed into the site-packages
folder that points to the parent environment when appropriate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-6-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow a9dbde71da mkvenv: add better error message for broken or missing ensurepip
Debian debundles ensurepip for python; NetBSD debundles pyexpat but
ensurepip needs pyexpat. Try our best to offer a helpful error message
instead of just failing catastrophically.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-5-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
John Snow dd84028ff9 python: add mkvenv.py
This script will be responsible for building a lightweight Python
virtual environment at configure time. It works with Python 3.6 or
newer.

It has been designed to:
- work *offline*, no PyPI required.
- work *quickly*, The fast path is only ~65ms on my machine.
- work *robustly*, with multiple fallbacks to keep things working.
- work *cooperatively*, using system packages where possible.
  (You can use your distro's meson, no problem.)

Due to its unique position in the build chain, it exists outside of the
installable python packages in-tree and *must* be runnable without any
third party dependencies.

Under normal circumstances, the only dependency required to execute this
script is Python 3.6+ itself. The script is *faster* by several seconds
when setuptools and pip are installed in the host environment, which is
probably the case for a typical multi-purpose developer workstation.

In the event that pip/setuptools are missing or not usable, additional
dependencies may be required on some distributions which remove certain
Python stdlib modules to package them separately:

- Debian may require python3-venv to provide "ensurepip"
- NetBSD may require py310-expat to provide "pyexpat" *
  (* Or whichever version is current for NetBSD.)

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230511035435.734312-4-jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00