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([2001:b07:6468:f312:1cc0:4e4e:f1a9:1745]) by smtp.gmail.com with ESMTPSA id b8sm4361808wrv.4.2020.08.21.05.58.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Aug 2020 05:58:11 -0700 (PDT) Subject: Re: [PATCH v2] configure: add support for pseudo-"in source tree" builds To: Kevin Wolf References: <20200820173124.243984-1-berrange@redhat.com> <814594a0-391c-01fb-a418-234e477793d3@redhat.com> <20200821100426.GB5153@linux.fritz.box> <20200821105439.GE5153@linux.fritz.box> From: Paolo Bonzini Message-ID: <6414fb85-7267-2382-dc2d-f10f6c1cb115@redhat.com> Date: Fri, 21 Aug 2020 14:58:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200821105439.GE5153@linux.fritz.box> Content-Language: en-US Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/21 02:43:55 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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=-1, RCVD_IN_MSPIKE_WL=-0.01, 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: Peter Maydell , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= , Stefan Hajnoczi , qemu-devel@nongnu.org, =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 21/08/20 12:54, Kevin Wolf wrote: >>> Sounds like it will be painful to switch between branches based on make >>> and branches based on meson. By extension, it will also be painful to >>> check out and build old versions for comparison, or doing that even more >>> than once during git bisect. :-( >> Not if you switch to out-of-tree builds... > I don't see what out-of-tree builds change about this unless I delete > and reconfigure them after each step? Even in those cases where I use > out-of-tree builds, I often reuse the same directory. In two ways: 1) bisection will rarely jump around the point where Meson was introduced. First, because if it coincides with the 5.1.0 release, then you know in advance if the problem was introduced before or after the merge. Second, because the bisection will quickly land on a merge commit, and then you can (just for going down the merged branch) use a separate out-of-tree build directory. 2) for the rare case of working on a branch that was developed pre-Meson and has not been rebased (or need not be rebased), you again use a separate out-of-tree build directory just for that one, and you don't have to worry about doing distclean or an incremental builds. Paolo