https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99426
--- Comment #8 from Nick Begg <nickbegg at gmail dot com> --- I've been testing with the proposed patch, and I am still getting the same errors.. /home/nick/inst/gcc-trunk-debug/bin/g++ -g -std=gnu++23 -Wall -Wextra -freport-bug --param=ggc-min-expand=10000 -MD -MT CMakeFiles/moduleMin.dir/main.cpp.o -MF CMakeFiles/moduleMin.dir/main.cpp.o.d -fmodules-ts -fmodule-mapper=CMakeFiles/moduleMin.dir/main.cpp.o.modmap -MD -fdeps-format=p1689r5 -x c++ -o CMakeFiles/moduleMin.dir/main.cpp.o -c /home/nick/src/moduleMin/main.cpp In module imported at /home/nick/src/moduleMin/main.cpp:3:1: modA: error: failed to read compiled module cluster 3000: Bad file data modA: note: compiled module file is ‘CMakeFiles/moduleMin.dir/modA.gcm’ modA: error: failed to read compiled module cluster 3001: Bad file data In file included from /home/nick/src/moduleMin/main.cpp:1: /home/nick/inst/gcc-trunk-debug/include/c++/14.0.1/format:1899:35: fatal error: failed to load pendings for ‘std::__format::__formatter_int’ 1899 | return _M_f._M_parse<char>(__pc); | ~~~~~~~~~~~~~~~~~~~^~~~~~ compilation terminated. I'm not sure if this is the same bug, or if I've uncovered a similar but distinct bug... Various values of --param=ggc-min-expand don't seem to make a difference.