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 X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B78FCC433E2 for ; Wed, 16 Sep 2020 13:32:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3C5DB2226B for ; Wed, 16 Sep 2020 13:32:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WQkoGNia" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C5DB2226B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53658 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIXXj-0001Yf-0R for qemu-devel@archiver.kernel.org; Wed, 16 Sep 2020 09:32:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54368) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIXVt-0000Gh-CB for qemu-devel@nongnu.org; Wed, 16 Sep 2020 09:30:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50693) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kIXVr-0005CS-CU for qemu-devel@nongnu.org; Wed, 16 Sep 2020 09:30:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600263018; 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: in-reply-to:in-reply-to:references:references; bh=HgJQykdvududQASZzz8oixzqyHR7Hmk1u5rLS/hlQfQ=; b=WQkoGNiaPDa9u/MLdjtW7qHSrForoddhAjc3CYv7kJ3HvNVE7NWYMetdoYpe4xewGwasOs 64yYV6DYafIb2Bmoxh1pOixvLrjCx+i1bT0xAzC6fK1MDT/NRdk6aM3meq1QFvkPJBragt oBia6ecoA7FB7aW5JeA0Egs2mt2mWuI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-474-FH6ojMgVMvOr5wj7To7cHA-1; Wed, 16 Sep 2020 09:30:14 -0400 X-MC-Unique: FH6ojMgVMvOr5wj7To7cHA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D621A81F03B; Wed, 16 Sep 2020 13:30:13 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-114-66.ams2.redhat.com [10.36.114.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C981319D6C; Wed, 16 Sep 2020 13:30:02 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 3D965113864A; Wed, 16 Sep 2020 15:30:01 +0200 (CEST) From: Markus Armbruster To: Peter Maydell Subject: Re: Python 3.5 EOL; when can require 3.6? References: <875z8eupyp.fsf@dusky.pond.sub.org> Date: Wed, 16 Sep 2020 15:30:01 +0200 In-Reply-To: (Peter Maydell's message of "Wed, 16 Sep 2020 13:30:49 +0100") Message-ID: <878sd9luhy.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=63.128.21.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/16 02:35:56 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.999, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , QEMU Developers , Michael Roth , Stefan Hajnoczi , Cleber Rosa , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Peter Maydell writes: > On Wed, 16 Sep 2020 at 08:43, Markus Armbruster wrote: >> We require Python 3.5. It will reach its "end of life" at the end of >> September 2020[*]. Any reason not to require 3.6 for 5.2? qemu-iotests >> already does for its Python parts. > > I think these things really ought to start with the converse question: > what is the important new thing that 3.6 brings to the table that > makes it worth moving our minimum requirement forward ? I'm chiefly after PEP 526 "Syntax for Variable Annotations" for much saner type hints. John's "[PATCH 00/37] qapi: static typing conversion pt1" already uses it, because not using it results in illegible code. Nice to have: PEP 498 "Literal String Interpolation" may let us improve QAPI code geneator readability. I haven't tried, yet. has the full list of new features. > If our code still works on 3.5 and there's nothing we really want to > do to the code that would be awkward to do without insisting on > 3.6, why should we irritate users by arbitrarily bumping the version > requirement ? > > Also as Dan notes upstream's EOL policies aren't very relevant, > because our policy is based on what distros ship. > > My broader point of view: C does not have any kind of infrastructure > like Rust's cargo or node's npm that makes it easy for a project to > say "we depend on these versions of these other packages" and > have them be satisified in a fairly painless-to-the-end-user/distro > way. So I prefer to take the approach of being as conservative as > possible about what we depend on, because the alternative tends > to be either pain for the person trying to compile QEMU (when they > have to scrabble around finding and building dependencies they > don't have conveniently to hand) or pain for us (when we have > to ship a dependency as a submodule). The default should be > "leave the version dependency where it is", not "bump the version > dependency as soon as we can". Understood. Anyone writing Python code in QEMU has paid a price for this policy. I certainly did. I'm okay with that as long as it helps more than it hurts. Lack of sane type hints is hurting QAPI developement. I believe requiring 3.6 will hurt QEMU less than hobbled QAPI development.