This finds homebrew's bash.
$ env -vvv -P $PATH bash
#env verbosity now at 2
#env verbosity now at 3
#env Searching: '/Users/beatys/.rbenv/shims:/Users/beatys/bin:/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:/sbin:/usr/sbin:/Applications/Docker.app/Contents/Resources/bin'
#env for file: 'bash'
#env matched: '/opt/homebrew/bin/bash'
#env executing: /opt/homebrew/bin/bash
#env arg[0]= '/opt/homebrew/bin/bash'
This does not.
$ env -vvv bash
#env verbosity now at 2
#env verbosity now at 3
#env executing: bash
#env arg[0]= 'bash'
Huh. Looking at the code shows a line
ptr = __DECONST(char *, str); /* XXXX Yes, very dodgy */
I'm not sure that's related, but it is a big type hammer.
#ifndef __DECONST
#define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
#endif
