https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118315
Bug ID: 118315 Summary: fmt library export module for -g, -Og or -O0 crashes compiler; -O1 and -O2 works Product: gcc Version: 14.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: ladislav.dobrovsky at gmail dot com Target Milestone: --- The fmt library (https://github.com/fmtlib/fmt) crashes the compiler with -g, -Og or O0; however -O1 and higher optimization level works well. I have recently encoutered the crash first on gcc 12, so I have tried versions 13.3.0 and 14.2. gcc 12 does not provide a bugreport file and claims "The bug is not reproducible, so it is likely a hardware or OS problem." However the later versions do produce a bugreport file, I attach the one for 14.2.0. The command: g++-14 -c -g -std=c++20 -Wall -Wextra -o fmt.o fmt.cc -I../include -fmodules-ts -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_DEBUG -freport-bug System info: $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 12 (bookworm) Release: 12 Codename: bookworm $ uname -a Linux dhcp227 6.1.0-26-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.112-1 (2024-09-30) x86_64 GNU/Linux