title: Segmentation Fault in PHP7
body: <p>We have encountered this weird issue with PHP 7.0. We are running Magento2's indexers on PHP 7.0 and have different outcomes on different environments.
  If we use CentOS, and get PHP 7.0 from either <a href="http://rpms.famillecollet.com/" rel="nofollow">Remi's Repo</a> or <a href="https://webtatic.com/projects/yum-repository/" rel="nofollow">Webtatic Repo</a>, we get a <strong>Segmentation Fault</strong> as follows:</p>
  
  <pre><code>Program received signal SIGSEGV, Segmentation fault.
  zend_mm_alloc_small (size=&lt;optimized out&gt;, bin_num=&lt;optimized out&gt;, heap=&lt;optimized out&gt;) at /usr/src/debug/php-7.0.1RC1/Zend/zend_alloc.c:1291
  1291                    heap-&gt;free_slot[bin_num] = p-&gt;next_free_slot;
  Missing separate debuginfos, use: debuginfo-install openssl-libs-1.0.1e-51.el7_2.1.x86_64
  (gdb) backtrace
  #0  zend_mm_alloc_small (size=&lt;optimized out&gt;, bin_num=&lt;optimized out&gt;, heap=&lt;optimized out&gt;) at /usr/src/debug/php-7.0.1RC1/Zend/zend_alloc.c:1291
  #1  zend_mm_alloc_heap (size=&lt;optimized out&gt;, heap=&lt;optimized out&gt;) at /usr/src/debug/php-7.0.1RC1/Zend/zend_alloc.c:1358
  #2  _emalloc (size=3, size@entry=32) at /usr/src/debug/php-7.0.1RC1/Zend/zend_alloc.c:2442
  #3  0x0000555555666840 in zend_string_alloc (persistent=0, len=4) at /usr/src/debug/php-7.0.1RC1/Zend/zend_string.h:121
  #4  php_pcre_replace_impl (pce=pce@entry=0x555555e76e40, subject_str=subject_str@entry=0x7fffd72fec68, subject=subject@entry=0x7fffd72fec80 "TypeId", subject_len=subject_len@entry=6, replace_val=replace_val@entry=0x7fffd2a393b0,
      is_callable_replace=is_callable_replace@entry=0, limit=&lt;optimized out&gt;, limit@entry=-1, replace_count=replace_count@entry=0x7fffffff7d5c) at /usr/src/debug/php-7.0.1RC1/ext/pcre/php_pcre.c:1217
  </code></pre>
  
  <p>But, if we use a compiled PHP7 version, there is no error. We also tried with a vagrant box configured with Ubuntu 14.0 and PHP 7.0.0 from ppa:ondrej/php-7.0 and no issues there either. </p>
  
  <p>Any ideas why this error occurs when using these specific repos? </p>
  
  <p><strong>Updated</strong>
  with 7.0.1 stack trace is different:</p>
  
  <pre><code>`Program received signal SIGSEGV, Segmentation fault.
  0x00007fffded34620 in ?? ()
  #0  0x00007fffded34620 in ?? ()
  #1  0x00005555557db82b in execute_ex (ex=&lt;optimized out&gt;) at /usr/src/debug/php-7.0.1/Zend/zend_vm_execute.h:414
  #2  0x000055555578ddd9 in dtrace_execute_ex (execute_data=&lt;optimized out&gt;) at /usr/src/debug/php-7.0.1/Zend/zend_dtrace.c:83
  </code></pre>