title: collect2.exe: error: ld returned 1 exit status
body: <p>Please I need help when I try to compile my .C to png</p>
  
  <pre><code>gcc --std=c99 -Wall -lz a.c -o a.png
  c:/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe: cannot find -lz
  collect2.exe: error: ld returned 1 exit status
  </code></pre>
  
  <p>What does this mean?</p>