title: How to check ruby-2.6.3 is using jemalloc ? I installed ruby-2.6.3 as $ rvm install 2.6.3 -C --with-jemalloc
body: <p>This command should show -ljemalloc but it is not. I could see it with ruby-2.4.3 and ruby-2.5.x but not with ruby-2.6.x</p>
  
  <pre><code>$ ruby -r rbconfig -e "puts RbConfig::CONFIG['LIBS']"
  -lm                                                                                                                                    
  $ cat /etc/environment
  
  
  PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so.1
  </code></pre>
  
  <p>I am using ubuntu 18 LTS and with other ruby version , I am getting the jemalloc file library as mention above</p>