Hello everyone, My Mac is Intell-powered macOS 15.7.7 (24G720) $ clang --version Apple clang version 17.0.0 (clang-1700.0.13.5) Target: x86_64-apple-darwin24.6.0 Thread model: posix InstalledDir: /Library/Developer/CommandLineTools/usr/bin I am a long-lasting developper on MacOS. For a few days, and probably since I have upgraded to MacOS Sequoia, all my C (or C++, etc) programs, even the simplest ever, fail to launch, once compiled with Apple's command line tools : $ clang simplest_ever_c_program.c $ ./a.out Killed: 9 The program is killed by MacOS before it launches. This occurs no matter with terminal I use (Zsh, bash, sh...). Removing / reinstalling command line tools did not fix the issue. There is no information printed in the Console. For some reason while investigating, I have come at some point to suspect a codesigning issue. **Indeed, signing the code after compilation seems to fix the problem : ** $ clang simplest_ever_c_program.c $ codesign -s - a.out Hello World ! Gratz : this progam could be run from the Terminal ! My questions : Why does MacOS suddenly started to kill my own executables compiled with clang ? Would you know how to fix the issue ? (may be an obscure new setting in MacOS preferences ?) Thanks much for your attention and in advance, Nicolas