Yosemite Nginx PHP crashes on curl_exec - php

Question

I have OSX 10.10 Yosemite with Nginx and PHP installed using Homebrew. I am trying some stuff with Symfony, but I have discovered that when I run my scripts, as soon as they reach the method call curl_exec, all execution is aborted and the server throws a 502 Bad Gateway error.
I created a separate script outside the Symfony scope and ran it with the PHP version I installed via Homebrew, and it worked perfectly fine. It is my assumption that there is an issue with PHP-FPM, however, as opposed to most other posts on StackOverflow, it's not like all PHP scripts are crashing, or that the curl extension isn't installed. Because all PHP scripts work, and curl method calls work, except for curl_exec.
Also, when the curl_exec function is called via Nginx, this is the line that is added to the error log:
2015/06/02 23:01:43 [error] 13355#0: *10 upstream prematurely closed
connection while reading response header from upstream, client:
127.0.0.1, server: mysubdomain.localhost, request: "GET /app_dev.php/users/create?XDEBUG_SESSION_START=19867 HTTP/1.1",
upstream: "fastcgi://127.0.0.1:9000", host: "mysubdomain.localhost:8080"
EDIT: As per nifr's request, here's what appears in my PHP error log:
[04-Jun-2015 09:25:58 America/Los_Angeles] PHP Warning: PHP Startup:
mcrypt: Unable to initialize module Module compiled with build
ID=API20131226,NTS PHP compiled with build ID=API20131226,NTS,debug
These options need to match in Unknown on line 0 [04-Jun-2015
09:26:03 America/Los_Angeles] PHP Warning: PHP Startup: mcrypt:
Unable to initialize module Module compiled with build
ID=API20131226,NTS PHP compiled with build ID=API20131226,NTS,debug
These options need to match in Unknown on line 0
However, this appears regardless of whether I use curl or not. It appears even when I so much as do a echo 'Hello World';, so I'm pretty sure this has nothing to do with curl_exec.
EDIT 2: I found another person who seems to have the same issue: php-fpm crashed when curl or file_get_contents request a https url
However, it is even more severe for them, because on my side, file_get_contents does not cause any crashes.
EDIT 3: nginx log:
[21-Oct-2015 11:39:39] WARNING: [pool www] child 73043 exited on
signal 11 (SIGSEGV) after 201.232240 seconds from start [21-Oct-2015
11:39:39] NOTICE: [pool www] child 73216 started