https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61758
Bug ID: 61758 Summary: std::chrono::steady_clock::now() no longer exported Product: gcc Version: 4.8.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: Martin.vGagern at gmx dot net Between 4.8.0 and 4.8.1, SVN commit 199331 changed the implementation of compatibility-chrono.cc. Up to that point, it basically included chrono.cc which provided implementations for system_clock and steady_clock, but bound them to specific symbol versions. That commit changes the approach to make use of an inline namespace, which is certainly more portable. The compatibility implementation was modified to no longer include chrono.cc but instead duplicate part of its functionality. And therein lies the rub: only PART of the implementation has been copied to the compatibility file. Now system_clock is included there, but steady_clock is not. Which causes ABI breakage, as observed in https://bugs.gentoo.org/513386.