[From nobody Mon May 4 05:21:05 2026 Received: (at submit) by bugs.debian.org; 19 Feb 2024 22:41:11 +0000 X-Spam-Checker-Version: SpamAssassin 3.4.6-bugs.debian.org_2005_01_02 (2021-04-09) on buxtehude.debian.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=4.0 tests=BAYES_00, BODY_INCLUDES_PACKAGE,DKIM_SIGNED,DKIM_VALID,FOURLA,FROMDEVELOPER, HAS_PACKAGE,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6-bugs.debian.org_2005_01_02 X-Spam-Bayes: score:0.0000 Tokens: new, 28; hammy, 149; neutral, 54; spammy, 1. spammytokens:0.936-+--view hammytokens:0.000-+--XDebbugsCc, 0.000-+--X-Debbugs-Cc, 0.000-+--HX-ME-Sender:xms, 0.000-+--HX-ME-Proxy:xmx, 0.000-+--H*RU:10.202.2.44 Return-path: <dkogan@debian.org> Received: from wfout7-smtp.messagingengine.com ([64.147.123.150]:58401) by buxtehude.debian.org with esmtps (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from <dkogan@debian.org>) id 1rcCJx-009iXD-S1 for submit@bugs.debian.org; Mon, 19 Feb 2024 22:41:11 +0000 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailfout.west.internal (Postfix) with ESMTP id A8CE01C000AC for <submit@bugs.debian.org>; Mon, 19 Feb 2024 17:35:04 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Mon, 19 Feb 2024 17:35:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:message-id :mime-version:reply-to:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t= 1708382104; x=1708468504; bh=yxU6rIGrfhe4MpafZI/GqUC6tmFMRswGIuV LclXPBtY=; b=QhJNQDAyqMVYx74loWMAoOSxWhpBi5JAnH2xUFPXrCf1hijiFLp ySlDPyDSyWAM/BgQAiWwmeIpf4SBytiBadLwv6J3HgetXK97nPZRJixhYMDVz7k9 E6lHI6GrAeDnq0x9Z8QjIDF/ih6mc0WzNWDqm/lh+eOaeI12eKvY9iQighqollHN YOKuHZgm/qqHBO2RCAYOuHrbF+h/eqdjS9bCWra4g5KU7lNdmHK1YBT+yajpl7SB mupsVsK2/pjH+5eTCg1xrkDydeVItEPa+X49cIiV30mRzHymdmp8jAQvCuq9BevS EYC8E374dLAbfBxliNXVhWgEj3zf9FC281A== X-ME-Sender: <xms:l9fTZYYj0pFwfZh0w2D_ytleQnPnsc7Cqgzalj4JYF3lCaau4Fuzqg> <xme:l9fTZTag4R1khnYUZnAWxKOT7OdGTEt3K5oTHAKyrE6k7P0k1mt3E_WY4hy816nfD -JGtdn8zIayAwMz> X-ME-Received: <xmr:l9fTZS8TKuwEN3LXocjli4sreXNtCIGVhpvHSxoOrYGXVmwGDoljVex2> X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrvdekgdduieduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefhvffufffkgggtsehttdertddttd dtnecuhfhrohhmpeffihhmrgcumfhoghgrnhcuoegukhhoghgrnhesuggvsghirghnrdho rhhgqeenucggtffrrghtthgvrhhnpefgkeeugeeuueekudetveetheejudeuhffhgfduje fhuedufffhuedthfehheffffenucffohhmrghinhepmhgrihhlqdgrrhgthhhivhgvrdgt ohhmnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepug hkohhgrghnseguvggsihgrnhdrohhrgh X-ME-Proxy: <xmx:l9fTZSrRXRGtt8YcI2JcLU_MDKgwKh5QB2-IuCUbWLpc_OCX6z6n2g> <xmx:l9fTZTqP2SnWpmbFF-eqirOdGAMnXvR-9Vm3Q3CPglqM_nEON2VUQg> <xmx:l9fTZQS0rh5XkgyIqq4TUt6aQl6eddBw0lrgboEg1K102gaM03JZ2Q> <xmx:mNfTZSTHbrK7Z9zs3WLDLGnJanFmC6stnuC8SJMXZkgoY9HPUFXtEE6d2Pk> Feedback-ID: if8c1469c:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA for <submit@bugs.debian.org>; Mon, 19 Feb 2024 17:35:03 -0500 (EST) From: Dima Kogan <dkogan@debian.org> To: Debian Bug Tracking System <submit@bugs.debian.org> Subject: libeigen3-dev: linking objects compiled with different flags may cause crashes Date: Mon, 19 Feb 2024 14:34:59 -0800 Message-ID: <87plwsaxrg.fsf@secretsauce.net> MIME-Version: 1.0 Content-Type: text/plain X-Greylist: delayed 360 seconds by postgrey-1.36 at buxtehude; Mon, 19 Feb 2024 22:41:08 UTC Delivered-To: submit@bugs.debian.org Package: libeigen3-dev Version: 3.4.0-4 Severity: normal X-Debbugs-Cc: none, Dima Kogan <dkogan@debian.org> Hello. I'm making this report to track the report in this mailing list thread: https://www.mail-archive.com/debian-science@lists.debian.org/msg13666.html In short: there's a known issue in Eigen that can create crashing binaries when using a very reasonable workflow. A description of the issue and minimized reproducer are here: https://www.mail-archive.com/debian-science@lists.debian.org/msg13710.html I propose to patch this in Debian and/or talk to Eigen upstream to eliminate the cause of the crash. A proposed patch appears here: https://www.mail-archive.com/debian-science@lists.debian.org/msg13857.html In my view, a questionable design choice in C++ allows the user to create crashing code, and Eigen expoloits this design choice to make this crashing possible. We cannot fix C++, but we can fix Eigen. The issue is that a templated function defined in a header generates a (weak symbol) copy of this function in EACH compile unit, and the linker then picks an arbitrary copy from the many compile units it is given. It is thus imperative that each copy is compatible with every other copy. Eigen breaks this requirement by using the preprocessor to select incompatible behaviors that might crash when linked together. The proposed patch eliminates this preprocessor-based variability. ]