Run gulp from Air Application

You are possibly pointing to a shortcut and not the real app.

what is the command-line you use in AIR ?
how did you install node/npm and gulp ? homebrew ? macport ? other?

try to run those commands from AIR native process and see their output

"which gulp"

"command -v 'gulp'"

try also
"printenv"

and look in PATH=...
see if the path where gulp is installed is there

also if some of those commands output to stderr instead of stdout
you will need to redirect stderr to stdout

for example:

java -version
will output to stderr

you would need to do

java -version 2>&1

so the stderr is redirected to stdout

some things to explore

1. "gulp"
if command not found
then use "which gulp" or "command -v gulp"
to find the full path, for ex it could returns "/usr/bin/gulp"

2. then try to call gulp with the fullpath eg. "/usr/bin/gulp"

3. the problem could be node
in gulp/gulp.js at master · gulpjs/gulp · GitHub
you can see "#!/usr/bin/env node"

maybe gulp can not find "node" with the "env" command

4. the problem could be your $PATH

if gulp is installed in a local directory like "/opt/local/bin"
maybe this path is not in the PATH environnement variable
and then even if gulp is installed it would not be found

If all that still does not work you could explore the idea
of converting gulp to an executable with such tools
as nexe, node-compile, node-compiler, etc.

and then distribute the exe within the AIR app