From debbugs-submit-bounces@debbugs.gnu.org Sun Oct 04 19:05:26 2020 Received: (at 43802) by debbugs.gnu.org; 4 Oct 2020 23:05:26 +0000 Received: from localhost ([127.0.0.1]:46947 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kPD4H-0000cJ-Vs for submit@debbugs.gnu.org; Sun, 04 Oct 2020 19:05:26 -0400 Received: from mailout.easymail.ca ([64.68.200.34]:56986) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kPD4F-0000c3-Cf for 43802@debbugs.gnu.org; Sun, 04 Oct 2020 19:05:25 -0400 Received: from localhost (localhost [127.0.0.1]) by mailout.easymail.ca (Postfix) with ESMTP id 976EE20ACE for <43802@debbugs.gnu.org>; Sun, 4 Oct 2020 23:05:17 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at emo06-pco.easydns.vpn Received: from mailout.easymail.ca ([127.0.0.1]) by localhost (emo06-pco.easydns.vpn [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rv6C7J8rRO35 for <43802@debbugs.gnu.org>; Sun, 4 Oct 2020 23:05:17 +0000 (UTC) Received: from laptop (unknown [108.162.141.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailout.easymail.ca (Postfix) with ESMTPSA id 5328020A92 for <43802@debbugs.gnu.org>; Sun, 4 Oct 2020 23:05:15 +0000 (UTC) From: Simon South To: 43802@debbugs.gnu.org Subject: Re: Knot: Linker runs very slowly and crashes during build Date: Sun, 04 Oct 2020 19:01:06 -0400 Message-ID: <87mu11egul.fsf@simonsouth.net> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Score: -2.3 (--) X-Debbugs-Envelope-To: 43802 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) So naturally, as soon as I submit the bug report something occurs to me that gets me unstuck. The delay and crash are occuring while libtool is using gcc to compile src/libzscanner/scanner.c, which appears to be generated at build time from the file scanner.c.t0 in the same directory. When I build Knot on my own, scanner.c has a size of 272 KB. When guix builds it, scanner.c somehow balloons out to 1.9 MB! So naturally gcc is going to need some time and space to make its way through all that code. In fact the build process actually points out NOTE: Compilation of scanner.c can take several minutes! So perhaps all this is completely expected. Still... 1.9 MB. Of C code. It's tempting to think something is going wrong here. (And anyway, why the huge discrepancy in file size?) I'm investigating. -- Simon South simon@simonsouth.net