From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,222ed89632aabb93 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit Received: by 10.224.177.12 with SMTP id bg12mr6765072qab.0.1343031974236; Mon, 23 Jul 2012 01:26:14 -0700 (PDT) Received: by 10.66.89.196 with SMTP id bq4mr1723151pab.26.1343031974150; Mon, 23 Jul 2012 01:26:14 -0700 (PDT) Path: a15ni65530154qag.0!nntp.google.com!x2no3191669qaj.0!news-out.google.com!b9ni37763115pbl.0!nntp.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!ctu-peer!news.nctu.edu.tw!goblin1!goblin.stu.neva.ru!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail From: Ludovic Brenta Newsgroups: comp.lang.ada Subject: Re: Free AMD Core Math Library (BLAS/LAPACK) + Ada Date: Sun, 15 Jul 2012 22:06:32 +0200 Organization: A noiseless patient Spider Message-ID: <87pq7wyek7.fsf@ludovic-brenta.org> References: <41b74e89-f112-4791-883d-236080652dbf@googlegroups.com> <37b4ba31-245e-44d1-9183-5c3367c88101@googlegroups.com> <2db42c1b-cfd4-4a6f-9e0c-ce269ddf00c5@googlegroups.com> <7cadf109-e24a-45eb-9d7c-354d8899eec4@googlegroups.com> <3f14ee5a-d055-4252-ab45-7ca512a23fac@googlegroups.com> <9cc53435-3c7f-4443-8209-5137b9377aca@googlegroups.com> <583b29e2-3f75-4b0a-8f1a-802b3d6e502c@googlegroups.com> <34139f6f-5905-4c9e-a873-0b2445a1fccd@googlegroups.com> <87txx8yl8t.fsf@ludovic-brenta.org> Mime-Version: 1.0 Injection-Info: mx04.eternal-september.org; posting-host="82e29ee268e884fcdafe06006538d3eb"; logging-data="29948"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+W4nWfxC785nex7bziiovk" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) Cancel-Lock: sha1:8qPF5RxnSfEkEUp+i8DPpGE9UcM= sha1:PSfIhZIjLKL4Ngkq9NE/m6kZ17U= Content-Type: text/plain; charset=us-ascii Date: 2012-07-15T22:06:32+02:00 List-Id: Simon Wright writes on comp.lang.ada: > Thanks for that. We really needed advice from someone who knows. > > By way of experiment, I removed liblapack-dev which left > /usr/lib/liblapack.{a,so} pointing to the now deleted /etc/alternatives/ > files. So I suppose the /usr/lib files get created when > update-alternatives is run after a new install of libfoo-dev? Correct but only if libfoo-dev participates in the alternatives system. Only few libraries do; BLAS is one but I don't know whether LAPACK also has alternatives. I'll let you know how I find that out without installing anything on my system: - go to http://www.debian.org/distrib/packages#search_contents - type liblapack.so in the Keyword field - tick "packages that contain files named like this" - choose the distribution: in your case , "Stable" (i.e. Debian 6 "Squeeze"). Results: /usr/lib/atlas-base/atlas/liblapack.so libatlas-base-dev /usr/lib/lapack/liblapack.so liblapack-dev So there is the answer: two -dev packages provide liblapack.so (the development-time symlink to the run-time shared library) in different subdirectories of /usr/lib. Therefore these two packages can be installed simultaneously. Also, no package provides /usr/lib/liblapack.so. Therefore the two packages above probably participate in the alternatives system. If the two packages are done correctly: - installing the first -dev package will initialize the alternatives system and create /usr/lib/liblapack.so to point to /usr/lib/$package/liblapack.so. - installing the second -dev package should ask you whether or not to change the default to be the new liblapack.so or tell you that it updated the alternative without asking (in the output of dpkg). - uninstalling one of the -dev packages should automatically change the alternative to point to the remaining liblapack.so; therefore you should never be left with a dangling symlink. If any of these things fail to happen (and you are sure you did not tamper with symlinks by hand), please file a bug against the -dev package that you installed or removed last. -- Ludovic Brenta.