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On Thu, Apr 20, 2017, at 17:17 CDT, "Walter Dnes" <waltdnes@××××××××.org> wrote: |
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> ...fun !NOT. If you're doing a fresh install, ***WITH A GCC5-BUILT |
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> INSTALL CD AND STAGE 3***, then yes, go for it. But changing horses in |
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> mid-stream can be painfull. Would it hurt to stay with 4.9.4 for the |
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> time being, assuming that you're not using prebuilt stuff like |
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> firefox-bin or libreoffice-bin? What would be the best way to go about |
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> it? |
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The technical discussion how to proceed with the new C++ abi happend two |
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years ago. We decided to do the only sensible thing in switching to the |
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new C++ abi. (And hopefully only see very minor issues in ABI |
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incompatibilities later on.) |
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It unfortunately involves rebuilding parts of your userland. |
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> A) Would 5.4.0 be slotted separately, and 4.9.4 left as the default? |
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> B) Add "-D_GLIBCXX_USE_CXX11_ABI=0" to CFLAGS and CXXFLAGS |
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> C) Mask out ">sys-devel/gcc-4.99" |
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> D) Allow "--with-default-libstdcxx-abi=gcc4-compatible" via a USE flag? |
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(A-C) gcc-5.4.0 and gcc-4.9.4 are slotted separately. What is going to |
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be the default is entirely up to you. If overriding the ABI via (B) is |
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such a great idea is yours to decide. |
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(D) will definitely not happen. |
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> Maybe we should what many enterprises do with Windows; i.e. skip a |
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> version and go straight to gcc-6. |
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No. We already stabilized gcc-5. A future stabilization of gcc-6/7 won't |
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be nearly as painful as this one. There is no reason to skip something. |
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Best, |
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Matthias |
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