autoload a class in slim behaves strangely - slim

Question

I developed an Slim-3 application on my local Vagrant (running on Windows) with standard Ubuntu 1604 env.
In my composer.json, I inserted the autoload directive:
"autoload": {
"psr-4": {
"btc\\": "src\btc"
}
}
And in my src\btc folder I created a few classes all with namespace btc declaration at the top of each PHP class files.
In particular, I have an http.php file like this:
namespace btc;
class Http {
const SUCCESS_WITH_OUTPUT = 200;
const SUCCESS_WITH_NO_OUTPUT = 204;
const SUCCESS_POST_WITH_OUTPUT = 201; //CREATED
const FAIL_AUTH = 401;
const BAD_REQUEST = 400;
const FAIL_OTHERWISE = 403;
}
In my routes.php I have this reference:
$output = ['res' => 'Method not implemented', 'status'=>btc\Http::BAD_REQUEST];
This works fine in my local vagrant machine.
===========
Now I cloned the repo to deploy to my production machine.
composer update runs fine.
I ran composer dumpautoload one more time to create the autoload files.
Slim app runs OK in the sense that the routes are correctly mapped.
But it fails saying that class 'btc/Http' not found error.
I think this is due to the btc namespace not automatically loaded.
Did I miss anything here?
Thanks for your help.

Answer 1

I have located the error that caused this strange behavior: case sensitivity.
As my Linux Vagrant machine is running on Windows, it does NOT care about cases. So http.php and Http.php is the same.
But in a pure Linux env, these two are different.
Changed to Http.php and everything goes fine.

Answer 2

Please use a / for all paths in composer.
Example:
"autoload": {
"psr-4": {
"btc\\": "src/btc/"
}
}
Then run composer update.