cURL response body missing (data not shown) - php

Question

I'm working with a specific restful API on CakePHP 2.4.x, part of the API includes sending files via curl POST/PUT and we've been unable to replicate what we need in CakePHP's HttpSocket so opted for traditional curl. The attempts to use PHP's curl commands would output nothing at all (despite pauses to show they were running).
Setting up a shell_exec will output information but unfortunately we are not getting the response body which is important to save data or view specific error messages.
I'm adding everything I think is relevant to this issue (I am on OSX, local environment XAMPP). My cURL version prints:
curl 7.30.0 (x86_64-apple-darwin13.0) libcurl/7.30.0 SecureTransport zlib/1.2.5
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smtp smtps telnet tftp
Features: AsynchDNS GSS-Negotiate IPv6 Largefile NTLM NTLM_WB SSL libz
Deprecated PHP Code (This prints string(0) "" )
$ch = curl_init();
curl_setopt ($ch, CURLOPT_HTTPHEADER, Array(
"Authorization: Bearer {$authInfo->access_token}",
'Accept: application/json'
));
curl_setopt($ch, CURLINFO_HEADER_OUT, true);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible;)");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
$post[$data['file']['name']] = '#' . $data['file']['location'];
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
curl_setopt($ch, CURLOPT_URL, $url);
$response = curl_exec($ch);
pr($post); // print_r wrapper
pr(curl_getinfo($ch));
var_dump($response);
curl_close($ch);
Shell Exec Code
This code works fine in actually doing what we want with the API, the only issue is we're not getting the response body.
$command = Configure::read('DM.CurlBinary') . ' -sb -k -v -X POST ';
$command .= $url . ' -F "' . $data['file']['name'] . '=#' . $data['file']['location'] . '"';
$command .= ' -H "AUTHORIZATION: Bearer ' . $authInfo->access_token . '"';
$command .= ' -H "ACCEPT: application/json" -H "EXPECT: 100-continue"';
$output = shell_exec($command);
pr($output); // print_r wrapper
pr($command);
Actual CURL Command
curl -sb -k -v -X POST https://idolcamp.idol.io/api/v1/tracks/857707/records -F "record[new_file]=#/Users/someuser/Documents/Development/DittoCake/app/tmp/Idol_857707.flac" -H "AUTHORIZATION: Bearer speacialtokengoeshere" -H "ACCEPT: application/json" -H "EXPECT: 100-continue"
Response
This shows as an 422 error because the file I am uploading already exists, I'd check it by its id but we have no response in order to get the id and check if it exists next time around.
Adding handle: conn: 0x7f8e3c004000
Adding handle: send: 0
Adding handle: recv: 0
Curl_addHandleToPipeline: length: 1
- Conn 0 (0x7f8e3c004000) send_pipe: 1, recv_pipe: 0
About to connect() to idolcamp.idol.io port 443 (#0)
Trying 212.83.129.122...
Connected to idolcamp.idol.io (212.83.129.122) port 443 (#0)
TLS 1.2 connection using TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Server certificate: *.idol.io
Server certificate: Gandi Standard SSL CA
Server certificate: UTN-USERFirst-Hardware
POST /api/v1/tracks/857707/records HTTP/1.1
User-Agent: curl/7.30.0
Host: idolcamp.idol.io
AUTHORIZATION: Bearer somespecialtoken
ACCEPT: application/json
EXPECT: 100-continue
Content-Length: 29600116
Content-Type: multipart/form-data; boundary=----------------------------3bd64d03cd9b
HTTP/1.1 100 Continue
} [data not shown]
HTTP/1.1 422 Unprocessable Entity
Server nginx is not blacklisted
Server: nginx
Date: Tue, 25 Aug 2015 15:08:00 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 0
Connection: keep-alive
X-Request-Id: 3803269a-18ea-4558-8623-08810a058030
X-Runtime: 1.112917
HTTP error before end of send, stop sending
Closing connection 0
API Doc: Request
API Doc: Response