What error are you running into, specifically?

Generally, this shouldn't be necessary, because we write an absolute path here and then load __init_script__.php, which will load your configured environment (including environment.append-paths).

If you have an old install which uses PHABRICATOR_ENV to select a custom config file, that won't make it, so options in your custom config file won't be loaded. The easiest fix is probably to create conf/local/ENVIRONMENT and write the environmental variable's value into that file. That will make sure your custom config file gets loaded.

(Generally, we've moved away from PHABRICATOR_ENV and stopped recommending it about a year ago, but older installs may still use it.)

Sorry, I have made some misunderstanding about this.
My problem is my php is installed in a custom path, and added to $PATH in ~/.bash_profile.
It seems the git hook does't load the bash_profile. So I try to fix it.

Hmm. I'd rather write this hook, then:

$full_php_path = Filesystem::resolveBinary('php');
$cmd = csprintf('exec %s -f %s %s "$@"', $full_php_path, $bin, $callsign);

Does that work on your system?

$bin mean it may be not a php script, I think make sure php is in PATH is better?
like this:

$php_dir = dirname(Filesystem::resolveBinary('php'));
$hook = "#!/bin/sh\nPATH={$php_dir}:\$PATH\n{$cmd}\n";

$bin will always be a PHP script -- and if it's not, putting php in PATH won't help with anything and will produce a more confusing error.