2. $ eselect news read 21
  3. 2018-06-23-mpfr-4-update
  4. Title dev-libs/mpfr 4 upgrade
  5. Author Matthias Maier <>
  6. Posted 2018-06-23
  7. Revision 1
  8. dev-libs/mpfr-4 introduced an ABI and soname change that has the potential
  9. of breaking the compiler toolchain. In order to minimize potential problems
  10. it is strongly recommended to rebuild mpc and gcc immediately after mpfr.
  11. You can do this by running
  12. emerge --ask --oneshot ">=dev-libs/mpfr-4" dev-libs/mpc sys-devel/gcc
  13. Detailed explanation:
  14. is used by (provided by dev-libs/mpc), as well as by
  15. internal executables (e.g. cc1, cc1plus) of sys-devel/gcc. Appropriate
  16. subslots in mpfr and slot-operators in dependencies in mpc and gcc will
  17. cause a rebuild of mpc and gcc after an upgrade of mpfr.
  18. However, after mpfr-4 is installed and mpc rebuiltd, but *before* gcc is
  19. rebuilt, gcc will be in an inconsistent state wherein symbols from
  20. incorrect library versions of mpfr might get used. This can result in
  21. segfaults and internal compiler errors. It is therefore important to
  22. rebuild gcc immmediately after mpc.
  23. A detailed update guide with troubleshoot section can be found on the wiki: