This is mostly a note to myself.

Sometimes, I have experienced output like the following:

# st = status
$ git st
Killed with signal 9

when running nix binaries. Most recently, it involved the git binary, but weirdly only when I used an alias 🤷

The Console.app output showed a line like:

CODE SIGNING: cs_invalid_page(0x1045dc000): p=16538[git] final status 0x23020200, denying page sending SIGKILL

This says to me that somehow macOS has decided my git binary is invalid, and the process execution is terminated with SIGKILL, the most fatal of all signals.

After doing some digging, I found this GitHub issue which mentioned nix store repair.

I ran the command

sudo nix store repair (command -v git)

which seemed to fix my problem nicely.