gdb compiler

if you install the Xcode command line tools, you get lldb, which is the debugger that works with the clang compiler install when you use

sudo xcode-select --install

gdb is usually a debugger. Do you possibly mean gcc or clang, which are compilers? If you want clang, Apple provides an installable version of that as the command line tools, or provides that as part of the Xcode download. The Apple downloads include the lldb debugger.

There are some add-on codesign steps referenced here:

https://formulae.brew.sh/formula/gdb#default

Failing that, check with whoever is maintaining that gdb homebrew recipe.

I’d expect gdb to install with gcc, so (if this is not already what you are trying) try installing gcc:

https://formulae.brew.sh/formula/gcc