https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127220
--- Comment #5 from Steve Sudit <stevensudit at gmail dot com> --- Yes, it is a clang bug that breaks libstdc++ code. I submitted the report and fix here because libstdc++ has taken cheap clang workarounds before when a patch came with the report (the LLVM-61763 blocks in <ranges>, commit be34a8b538c0 from 2023, and the <complex> case mentioned in PR 115740). Moreover, this incompatibility has significant consequences: with clang in C++26 mode, no format string with a dynamic width or precision compiles at all, and LLVM 73232 has been open since 2023 with no fix in sight. The attached patch keeps the header's behavior for gcc unchanged and does not impact code quality. I would suggest that, although the root cause lies with clang, libstdc++ is widely used with clang, so a workaround here has broad reach. If Jonathan would rather not carry it, that is of course his call.
