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Le 28/12/2009 22:04, Fabio Erculiani a écrit : |
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> On Mon, Dec 28, 2009 at 9:51 PM, David Leverton |
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> <levertond@××××××××××.com> wrote: |
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>> On Monday 28 December 2009 20:50:17 Fabio Erculiani wrote: |
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>>> What all this has to do with the fact that they are just build |
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>>> dependencies? Just wondering. |
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>> |
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>> They're not just build dependencies. They're required to use the library in a |
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>> certain way, namely to compile other programs against it. As long as we |
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>> don't have compile-against dependencies, the only correct way to express that |
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>> is RDEPEND (and also DEPEND because they're /also/ needed to build the |
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>> library itself). |
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> |
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> To me you are saying that DEPEND would work just fine. No? |
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No, but I understand why you're insisting. It took us a few weeks to |
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wrap our heads around this to understand it. |
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Let's take an example (bug #228211 but there are dozens more). |
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In this example, libfakekey does : #include <XTest.h> |
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and its configure.ac checks for "xtst.pc". Both files are provided by |
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x11-libs/libXtst so this dep is added to DEPEND and RDEPEND. |
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The problem comes from libXtst's XTest.h which #includes <XInput.h> |
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which was provided by x11-proto/inputproto [1]. |
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inputproto is/was a build-time dep of libXtst. |
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- libXtst _directly_ requires inputproto at build-time only |
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- libXtst _directly_ requires libXi at build-time and run-time |
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However : |
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- requiring libXtst at build-time _also_ requires inputproto. |
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For most users out there, this would never be a problem since most |
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Gentoo users always keep build-time deps on their systems. |
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The problem arises for people who only keep run-time deps, usually for |
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binary packages. inputproto being a DEPEND-only dep of libXtst, binary |
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users will never get inputproto when they build libfakekey. |
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So there were 3 solutions : |
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1) add explicit deps in _all_ packages that DEPEND on libXtst to _also_ |
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depend on inputproto even if they don't use it at all (most don't, they |
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just use XTest functions). |
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2) add inputproto to libXtst's DEPEND and RDEPEND |
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3) modify EAPI to add a new *DEPEND variable to cater X's very special |
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needs. |
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Solution #1 is error prone. If we "fix" ebuilds now, new ebuilds might |
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pop up later with "broken" dependencies. No go. |
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Solution #3 really isn't for me. I tried getting near PMS and I got bit. |
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If anyone wants to do this, I'll help, but I won't do this on my own. |
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So we went with solution #2. Yes, it does add nasty little headers on a |
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binary distribution, but that was a far better compromise than any of |
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the other 2 solutions. |
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Really, the correct solution (please _listen_ and _trust_ me on this) is |
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to add a new dependency variable to EAPI to correctly describe how X |
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headers and libs really work. That's solution #3. I agree with you, |
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pulling protos in both DEPEND and RDEPEND is a hack, but it's *much* |
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better than the other alternatives. |
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Rémi |
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[1] This file is now part of libXi, but the problem has now shifted to |
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XI.h, so it's still going to be the exact same problem today, but for |
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the sake of simplicity, I'll keep it short. |
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