Non fatal build errors without imagemin-gifsicle installed

[raventeller]

No where in the install docs is imagemin-gifsicle mentioned dependancy.
I was building this on archliux so there may be something weird happening becasue the OS is configed differently - but in this case I don't think so because after I did npm install imagemin-gifsicle I didn't get the build errors any more.
Error

Running "concurrent:dist" (concurrent) task
Warning: Loading "imagemin.js" tasks...ERROR
>> Error: Cannot find module 'imagemin-gifsicle'
Loading "grunt-karma.js" tasks...ERROR
>> TypeError: Cannot read property 'prototype' of undefined
Warning: Task "imagemin" not found. Use --force to continue.

Aborted due to warnings.


Execution Time (2017-01-17 13:20:44 UTC)
loading tasks  8ms  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 89%
Total 9ms Use --force to continue.
    
    Aborted due to warnings.