Initially bug was reported as a crash of llvm-tblgen tool: https://bugs.gentoo.org/749162. Small reproducer: $ cat a.cc #include <mutex> static std::once_flag of; static std::recursive_mutex * pm = nullptr; int main() { std::call_once(of, []() { pm = new std::recursive_mutex; }); } $ g++-10.2.0 a.cc -o a -ggdb3 && ./a terminate called after throwing an instance of 'std::system_error' what(): Unknown error -1 Aborted (core dumped) $ g++-10.2.0 a.cc -o a -pthread && ./a All gcc versions are affected (at least 6.5.0 and above). Backtrace: """ Reading symbols from ./a... (gdb) run Starting program: /tmp/a terminate called after throwing an instance of 'std::system_error' what(): Unknown error -1 Program received signal SIGABRT, Aborted. __GI_raise (sig=<optimized out>) at ../sysdeps/unix/sysv/linux/raise.c:49 49 return ret; (gdb) bt #0 __GI_raise (sig=<optimized out>) at ../sysdeps/unix/sysv/linux/raise.c:49 #1 0x00007ffff7a1c536 in __GI_abort () at abort.c:79 #2 0x00007ffff7dad961 in __gnu_cxx::__verbose_terminate_handler () at /usr/src/debug/sys-devel/gcc-11.0.0_pre9999/gcc-11.0.0_pre9999/libstdc++-v3/libsupc++/vterminate.cc:95 #3 0x00007ffff7ddcd9a in __cxxabiv1::__terminate (handler=<optimized out>) at /usr/src/debug/sys-devel/gcc-11.0.0_pre9999/gcc-11.0.0_pre9999/libstdc++-v3/libsupc++/eh_terminate.cc:48 #4 0x00007ffff7ddce05 in std::terminate () at /usr/src/debug/sys-devel/gcc-11.0.0_pre9999/gcc-11.0.0_pre9999/libstdc++-v3/libsupc++/eh_terminate.cc:58 #5 0x00007ffff7ddd098 in __cxxabiv1::__cxa_throw (obj=<optimized out>, tinfo=0x7ffff7f6f948 <typeinfo for std::system_error>, dest=0x7ffff7e0a570 <std::system_error::~system_error()>) at /usr/src/debug/sys-devel/gcc-11.0.0_pre9999/gcc-11.0.0_pre9999/libstdc++-v3/libsupc++/eh_throw.cc:95 #6 0x00007ffff7db0c7f in std::__throw_system_error (__i=-1) at /usr/src/debug/sys-devel/gcc-11.0.0_pre9999/build/x86_64-pc-linux-gnu/libstdc++-v3/include/ext/new_allocator.h:89 #7 0x000055555555531d in std::call_once<main()::<lambda()> >(std::once_flag &, struct {...} &&) (__once=..., __f=...) at /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/g++-v10/mutex:743 #8 0x000055555555521a in main () at a.cc:7 """ https://stackoverflow.com/questions/8649828/what-are-the-correct-link-options-to-use-stdthread-in-gcc-under-linux suggests -pthread has to be used. Would it be feasible to convert this error as any of: 1. Link-time error that would complain about missing pthread_once symbol. 2. Successful run if libpthread is not present (probably not easy as libpthread can be loaded dynamically at a later point in program's runtime).
$ LANG=C gcc-11.0.0 -v Using built-in specs. COLLECT_GCC=/usr/bin/gcc-11.0.0 COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-11.0.0_pre9999/work/gcc-11.0.0_pre9999/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/11.0.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/include/g++-v11 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/python --enable-languages=c,c++,go,jit,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 11.0.0_pre9999 p4, commit 6b55fa29adf4d643e61388bf01a4509b0b041d17' --disable-esp --enable-libstdcxx-time --enable-host-shared --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libssp --disable-libada --disable-systemtap --enable-valgrind-annotations --enable-vtable-verify --without-zstd --enable-lto --with-isl --disable-isl-version-check --enable-default-pie --enable-default-ssp Thread model: posix Supported LTO compression algorithms: zlib gcc version 11.0.0 20201015 (experimental) (Gentoo 11.0.0_pre9999 p4, commit 6b55fa29adf4d643e61388bf01a4509b0b041d17)
AFAIU '-1' comes from https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libgcc/gthr-posix.h;h=965247602acf11f81c5fa009c7ee48eb55cbacca;hb=HEAD#l696 696 static inline int 697 __gthread_once (__gthread_once_t *__once, void (*__func) (void)) 698 { 699 if (__gthread_active_p ()) 700 return __gthrw_(pthread_once) (__once, __func); 701 else 702 return -1; 703 } where '__gthread_active_p ()' returns false: (gdb) call __gthread_active_p() $2 = 0 That is defined in https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libgcc/gthr-posix.h;h=965247602acf11f81c5fa009c7ee48eb55cbacca;hb=HEAD#l236 236 #ifdef __GLIBC__ 237 __gthrw2(__gthrw_(__pthread_key_create), 238 __pthread_key_create, 239 pthread_key_create) 240 # define GTHR_ACTIVE_PROXY __gthrw_(__pthread_key_create) 241 #elif defined (__BIONIC__) 242 # define GTHR_ACTIVE_PROXY __gthrw_(pthread_create) 243 #else 244 # define GTHR_ACTIVE_PROXY __gthrw_(pthread_cancel) 245 #endif 246 247 static inline int 248 __gthread_active_p (void) 249 { 250 static void *const __gthread_active_ptr 251 = __extension__ (void *) >HR_ACTIVE_PROXY; 252 return __gthread_active_ptr != 0; 253 } Both of symbols are weak, unbound to libpthread and unversioned (for non-working case): $ g++-11.0.0 a.cc -o a && x86_64-pc-linux-gnu-nm -D a | fgrep -i pthread w __pthread_key_create w pthread_once $ g++-11.0.0 a.cc -o a -pthread && x86_64-pc-linux-gnu-nm -D a | fgrep -i pthread w __pthread_key_create@@GLIBC_2.2.5 w pthread_once@@GLIBC_2.2.5
Looks like a dup of PR 55394
Ah, yes! *** This bug has been marked as a duplicate of bug 55394 ***