https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69075
--- Comment #6 from Charles <charles.frasch at gmail dot com> --- This appears to have been fixed for at least 8.3. Mikhail's reduced version compiles without error for both c++14 and 17. Note that I added the -c flag. cfrasch@cff-ultra:~/gcc_bug_69075$ g++ -std=c++14 -flto -O3 -fdevirtualize-at-ltrans --param early-inlining-insns=15 -c test2.cc cfrasch@cff-ultra:~/gcc_bug_69075$ g++ -std=c++17 -flto -O3 -fdevirtualize-at-ltrans --param early-inlining-insns=15 -c test2.cc Here is my gcc build info: cfrasch@cff-ultra:~/gcc_bug_69075$ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-pc-linux-gnu/8.3.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-8.3.0/configure --enable-languages=c,c++ --enable-linker-build-id --disable-multilib Thread model: posix gcc version 8.3.0 (GCC) Unfortunately I no longer have access to either the original source code or the environment under which the failure was originally reported. Thank you for your continued work on gcc.