Crash when use `gz sim` with invalid combo (`sdf file` and `--playback` flag)

[XINJIANGMO]

Environment

• OS Version: Ubuntu 24.04
• Source or binary build?
  source,gz-sim10

Description

• Expected behavior: only error messages , no crash
• Actual behavior: gazebo crashes

Steps to reproduce

1. gz sim gz sim shapes.sdf --playback ~/.gz/sim/log/[anyone you have recorded]
2. crash

Output

(2025-10-17 18:02:27.986) [error] [gz.cc:453] Both an SDF file and playback flag are specified. Only specify one.
terminate called without an active exception
Stack trace (most recent call last):
#11   Object "", at 0xffffffffffffffff, in 
#10   Object "/home/momo/gz_jetty/install/libexec/gz/sim10/gz-sim-main", at 0x5ef0007e6c84, in _start
#9    Source "../csu/libc-start.c", line 360, in __libc_start_main_impl [0x75ae86c2a28a]
#8    Source "../sysdeps/nptl/libc_start_call_main.h", line 58, in __libc_start_call_main [0x75ae86c2a1c9]
#7    Source "/home/momo/gz_jetty/src/gz-sim/src/cmd/sim_main.cc", line 525, in main [0x5ef0007f068f]
        522:     #endif
        523: 
        524:     gzdbg << "Shutting down gz-sim-server" << std::endl;
      > 525:   }
        526:   else
        527:   {
        528:     if(opt->launchServer)
#6  | Source "/usr/include/c++/13/bits/std_thread.h", line 173, in __terminate
    |   171:     {
    |   172:       if (joinable())
    | > 173: 	std::__terminate();
    |   174:     }
      Source "/usr/include/x86_64-linux-gnu/c++/13/bits/c++config.h", line 322, in ~thread [0x5ef0007fb50a]
        319:   inline void __terminate() _GLIBCXX_USE_NOEXCEPT
        320:   {
        321:     void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
      > 322:     terminate();
        323:   }
        324: #pragma GCC visibility pop
        325: }
#5    Source "../../../../src/libstdc++-v3/libsupc++/eh_terminate.cc", line 58, in terminate [0x75ae870a5a54]
#4    Source "../../../../src/libstdc++-v3/libsupc++/eh_terminate.cc", line 48, in __terminate [0x75ae870bb0d9]
#3    Source "../../../../src/libstdc++-v3/libsupc++/vterminate.cc", line 95, in __verbose_terminate_handler [0x75ae870a5ff4]
#2    Source "./stdlib/abort.c", line 79, in abort [0x75ae86c288fe]
#1    Source "../sysdeps/posix/raise.c", line 26, in raise [0x75ae86c4527d]
#0  | Source "./nptl/pthread_kill.c", line 89, in __pthread_kill_internal
    | Source "./nptl/pthread_kill.c", line 78, in __pthread_kill_implementation
      Source "./nptl/pthread_kill.c", line 44, in __pthread_kill [0x75ae86c9eb2c]
Aborted (Signal sent by tkill() 264450 1000)

[XINJIANGMO]

An invalid argument combination triggers an early exit while one or more std::threads remain joinable; when main() returns, their destructors (not joined or detached) call std::terminate, resulting in terminate called without an active exception
I prefer fixing the issue in sim_main.cc by adding check in main.

CLI11_PARSE(app, argc, argv);
// add check for opt
if (!opt->file.empty() && !opt->playback.empty())
{
gzerr << "Both an SDF file and playback flag are specified. Only specify one."
<< std::endl;
return -1;
}