Corona's Loader Does Not Recognize `package.path`

-- The "Penlight" folder is a git submodule located within
-- my Corona app's resource folder. Penlight modules are
-- lazily loaded when referenced by `pl`.
--
-- https://github.com/stevedonovan/Penlight
-- http://stevedonovan.github.io/Penlight/api/topics/01-introduction.md.html
package.path = "Penlight/lua/pl/?.lua;" .. package.path
local pl = require 'import_into' ()

-- When building the app for the iOS Simulator, the app is
-- unable to find "Penlight/lua/pl/import_into.lua", even though it exists
-- on disk. The warning that appears in the console suggests that the
-- Penlight folder is not being included with the rest of the app's source.
-- Any advice on how to sanely use Penlight with my project?
--
-- <Warning>: Runtime error
--   module 'import_into' not found:resource (import_into.lu) does not exist in archive
--     no field package.preload['import_into']
--     no file 'Penlight/lua/pl/import_into.lua'
--     no file '/Users/name/Library/Application Support/iPhone Simulator/7.1/Applications/CEE02776-DBCD-43EC-8F2C-317A69C3D57B/My.app/import_into.lua'