gcc 7.3 LTO (-flto) crash (SIGSEGV) on exit () / static variable?

I had an old app that I need to maintain. Thousands of lines of code.

When I switched to the gcc 7.3 compiler and I enabled -flto application started to crash o exit:

(gdb) bt
#0  0x00000000 in ?? ()
#1  0x1ee0c6b0 in ?? () from /lib/libc.so.6
#2  0x1ee0c840 in exit () from /lib/libc.so.6
#3  0x1edf0d5c in ?? () from /lib/libc.so.6
#4  0x1edf0f10 in __libc_start_main () from /lib/libc.so.6
#5  0x00000000 in ?? ()

When I removed -flto option app stopped crashing.

I've traced that unused static variable in a body of one of functions caused the problem:

  static std::vector<C_Param*>    vpParam;

When I removed 'static' or removed variable at all app stopped crashing.

This is very strange to me because the variable is not used and only happens with the -flto option.

What could be the main cause?