[SOLVED] Fixed: Lossy operations are not currently supported

kinda fixed

if you getting

Warning: Running "imagemin:dist" (imagemin) task
Warning: Command failed: ** Error: Lossy operations are not currently supported
Use --force to continue.

just uninstall optipng

  sudo apt-get remove optipng
 

Source: http://subdigit.com/blog/project-bootstrapping/