From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D35DAC77B7A for ; Tue, 16 May 2023 11:00:05 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pysP9-0001S6-Md; Tue, 16 May 2023 06:59:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pysP6-0001JU-AC for qemu-devel@nongnu.org; Tue, 16 May 2023 06:59:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pysOm-00085v-8f for qemu-devel@nongnu.org; Tue, 16 May 2023 06:59:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684234759; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6b0+bnZkKtxie9s9t4csc1mAslPRHvp5lMn0BqGXUxg=; b=L7EodiltoKFOYp8Uxq04XWaL9DMofC5V7+s7Ld1N//MqAbJYiKppBlGr3vNiMpO6qBWM1V NFTB6GsfXAP0WJcitFP+dqkSgwF2NUSCB+Za7sqYOUxb5IVTsAJWqJ9OY7climNzuTBonw hd8Of8817EBqpUvBXxpnvk1QYWKsOjo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-499-ht_lHB0KP7yfDkYW8U9huQ-1; Tue, 16 May 2023 06:59:16 -0400 X-MC-Unique: ht_lHB0KP7yfDkYW8U9huQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D7B36800047; Tue, 16 May 2023 10:59:15 +0000 (UTC) Received: from avogadro.lan (unknown [10.39.192.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id 004A9492B00; Tue, 16 May 2023 10:59:14 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Cc: jsnow@redhat.com, philmd@linaro.org, berrange@redhat.com Subject: [PATCH v2 05/27] mkvenv: add nested venv workaround Date: Tue, 16 May 2023 12:58:46 +0200 Message-Id: <20230516105908.527838-5-pbonzini@redhat.com> In-Reply-To: <20230516105908.527838-1-pbonzini@redhat.com> References: <20230516105908.527838-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: John Snow 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 Signed-off-by: John Snow Message-Id: <20230511035435.734312-6-jsnow@redhat.com> Signed-off-by: Paolo Bonzini --- python/scripts/mkvenv.py | 91 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 86 insertions(+), 5 deletions(-) diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py index 09a6f300d541..2a3d73a51db4 100644 --- a/python/scripts/mkvenv.py +++ b/python/scripts/mkvenv.py @@ -38,8 +38,10 @@ import logging import os from pathlib import Path +import site import subprocess import sys +import sysconfig from types import SimpleNamespace from typing import Any, Optional, Union import venv @@ -52,6 +54,11 @@ logger = logging.getLogger("mkvenv") +def inside_a_venv() -> bool: + """Returns True if it is executed inside of a virtual environment.""" + return sys.prefix != sys.base_prefix + + class Ouch(RuntimeError): """An Exception class we can't confuse with a builtin.""" @@ -60,10 +67,9 @@ class QemuEnvBuilder(venv.EnvBuilder): """ An extension of venv.EnvBuilder for building QEMU's configure-time venv. - As of this commit, it does not yet do anything particularly - different than the standard venv-creation utility. The next several - commits will gradually change that in small commits that highlight - each feature individually. + The primary difference is that it emulates a "nested" virtual + environment when invoked from inside of an existing virtual + environment by including packages from the parent. Parameters for base class init: - system_site_packages: bool = False @@ -78,6 +84,18 @@ class QemuEnvBuilder(venv.EnvBuilder): def __init__(self, *args: Any, **kwargs: Any) -> None: logger.debug("QemuEnvBuilder.__init__(...)") + # For nested venv emulation: + self.use_parent_packages = False + if inside_a_venv(): + # Include parent packages only if we're in a venv and + # system_site_packages was True. + self.use_parent_packages = kwargs.pop( + "system_site_packages", False + ) + # Include system_site_packages only when the parent, + # The venv we are currently in, also does so. + kwargs["system_site_packages"] = sys.base_prefix in site.PREFIXES + if kwargs["with_pip"]: check_ensurepip() @@ -86,11 +104,71 @@ def __init__(self, *args: Any, **kwargs: Any) -> None: # Make the context available post-creation: self._context: Optional[SimpleNamespace] = None + def get_parent_libpath(self) -> Optional[str]: + """Return the libpath of the parent venv, if applicable.""" + if self.use_parent_packages: + return sysconfig.get_path("purelib") + return None + + @staticmethod + def compute_venv_libpath(context: SimpleNamespace) -> str: + """ + Compatibility wrapper for context.lib_path for Python < 3.12 + """ + # Python 3.12+, not strictly necessary because it's documented + # to be the same as 3.10 code below: + if sys.version_info >= (3, 12): + return context.lib_path + + # Python 3.10+ + if "venv" in sysconfig.get_scheme_names(): + lib_path = sysconfig.get_path( + "purelib", scheme="venv", vars={"base": context.env_dir} + ) + assert lib_path is not None + return lib_path + + # For Python <= 3.9 we need to hardcode this. Fortunately the + # code below was the same in Python 3.6-3.10, so there is only + # one case. + if sys.platform == "win32": + return os.path.join(context.env_dir, "Lib", "site-packages") + return os.path.join( + context.env_dir, + "lib", + "python%d.%d" % sys.version_info[:2], + "site-packages", + ) + def ensure_directories(self, env_dir: DirType) -> SimpleNamespace: logger.debug("ensure_directories(env_dir=%s)", env_dir) self._context = super().ensure_directories(env_dir) return self._context + def create(self, env_dir: DirType) -> None: + logger.debug("create(env_dir=%s)", env_dir) + super().create(env_dir) + assert self._context is not None + self.post_post_setup(self._context) + + def post_post_setup(self, context: SimpleNamespace) -> None: + """ + The final, final hook. Enter the venv and run commands inside of it. + """ + if self.use_parent_packages: + # We're inside of a venv and we want to include the parent + # venv's packages. + parent_libpath = self.get_parent_libpath() + assert parent_libpath is not None + logger.debug("parent_libpath: %s", parent_libpath) + + our_libpath = self.compute_venv_libpath(context) + logger.debug("our_libpath: %s", our_libpath) + + pth_file = os.path.join(our_libpath, "nested.pth") + with open(pth_file, "w", encoding="UTF-8") as file: + file.write(parent_libpath + os.linesep) + def get_value(self, field: str) -> str: """ Get a string value from the context namespace after a call to build. @@ -183,9 +261,12 @@ def make_venv( # pylint: disable=too-many-arguments ) style = "non-isolated" if builder.system_site_packages else "isolated" + nested = "" + if builder.use_parent_packages: + nested = f"(with packages from '{builder.get_parent_libpath()}') " print( f"mkvenv: Creating {style} virtual environment" - f" at '{str(env_dir)}'", + f" {nested}at '{str(env_dir)}'", file=sys.stderr, ) -- 2.40.1