From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1McN22-0004Nu-1a for garchives@archives.gentoo.org; Sat, 15 Aug 2009 17:27:06 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 809A3E043D; Sat, 15 Aug 2009 17:27:04 +0000 (UTC) Received: from mail-ew0-f210.google.com (mail-ew0-f210.google.com [209.85.219.210]) by pigeon.gentoo.org (Postfix) with ESMTP id 42BA9E043D for ; Sat, 15 Aug 2009 17:27:04 +0000 (UTC) Received: by ewy6 with SMTP id 6so312491ewy.34 for ; Sat, 15 Aug 2009 10:27:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:to:subject:date :user-agent:references:in-reply-to:mime-version:content-type :content-transfer-encoding:message-id; bh=2si6LMSv4SME9dgJZDg4QIm8s8D40APAuu27c6Gqznk=; b=XJHrLny08kKtJizv27ezLjOo53NxwYZFGkxrHQPREuNWkzzzQB8qySwyHmsPQUQP31 gdI8hY4DGTU+z/wyV4lzKNiduMZ85muaNf8KWNtzAc2B+FXjncP/zwXy/PBVOK5JyYP5 2137tShU6Hj+7RCyG6aZ7OxUO0OeJtSY8zxZA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:references:in-reply-to:mime-version :content-type:content-transfer-encoding:message-id; b=KfKyBwElL3V8FUvJWNj1TWk/fH1o5jATBSidaTsOCkitjbco4ggvPICzRutCPB0hdg mlhFrR+tJ+nRV/7H3BulJnqigRy94wv+d0t+OV84tyc41nNkUZ8Dl5Qm8ZJx3kGKlJVj LozBqpz2YytCE4i1mC1q+P2rq5VuXkY7mV7DY= Received: by 10.210.86.1 with SMTP id j1mr993653ebb.61.1250357223744; Sat, 15 Aug 2009 10:27:03 -0700 (PDT) Received: from nazgul.localnet ([196.210.202.145]) by mx.google.com with ESMTPS id 28sm7300758eyg.42.2009.08.15.10.27.02 (version=SSLv3 cipher=RC4-MD5); Sat, 15 Aug 2009 10:27:03 -0700 (PDT) From: Alan McKinnon To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: Gcc 4.3.4 ---> 4.4.1 Date: Sat, 15 Aug 2009 19:25:39 +0200 User-Agent: KMail/1.12.0 (Linux/2.6.30-gentoo-r4; KDE/4.3.0; x86_64; ; ) References: <20090814231756.GA9536@crowfix.com> <5bdc1c8b0908150942y37996f4dtdf471a7456d64565@mail.gmail.com> <200908151906.55222.dirk.heinrichs@online.de> In-Reply-To: <200908151906.55222.dirk.heinrichs@online.de> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <200908151925.39832.alan.mckinnon@gmail.com> X-Archives-Salt: 6318d0ac-5b01-48ba-a41b-e6e747322556 X-Archives-Hash: 8d1d4b69f521c55bf5a22c34c722bf83 On Saturday 15 August 2009 19:06:54 Dirk Heinrichs wrote: > Am Samstag 15 August 2009 18:42:11 schrieb Mark Knecht: > > Code Listing 2.2: Rebuilding system > > > > # emerge -eav system > > # emerge -eav world > > I still wonder about this one. Doesn't world include system, so that the > above would result in rebuilding a vast amount of packages twice? The logic goes like this: rebuilding system rebuilds (amongst other things) the entire toolchain. You then use that complete toolchain to rebuild itself in the second pass, along with everything else in world. The end effect is that you are 100% guaranteed that ever bit of code was built with the new compiler (taking advantage of any new features in that compiler). A common misunderstanding is that you have to rebuild gcc twice. This is not true as gcc's own build system in fact builds gcc three times and does a binary diff between the last two, the build only proceeds if they are bit-for- bit identical. So there is no need for portage to redo this as gcc already did it. But the same cannot be said for everything else in the toolchain. So the above advice resolves down to it being the minimum necessary to absolutely guarantee consistency throughout the entire system. Anything less could possibly leave small gaps open. In a way, building system then world, is exactly the same thing that binary distros do with a new release. They too can guarantee that the entire distro was built with the very compiler they ship. -- alan dot mckinnon at gmail dot com