kernel_require.rb: cannot load such file

Question

I used gulp to build a html project. For some css staff,I used compass to build. I have task as follow

gulp.task('compass',function(){
    gulp.src('public_html/app/scss/style.scss')
            //.pipe(plumber())
            .pipe(compass({
                config_file: './config.rb',
                css: 'public_html/app/css',
                sass: 'public_html/app/scss',
                require: ['susy']
            }))
            //.pipe(autoprefixer('last 2 versions'))
            .pipe(gulp.dest('public_html/app/css'))
            .pipe(reload({stream:true}));
});

When I build as gulp compass, I have error as

LoadError on line ["55"] of ~/.rbenv/versions/2.3.1/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb: cannot load such file -- susy
Run with --trace to see the full backtrace


events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: Compass failed

I have that file kernel_require.rb in the exact folder. I export PATH as

 export PATH=$PATH:~/.rbenv/versions/2.3.1/lib   
export PATH=$PATH:~/.rbenv/versions/2.3.1/lib/ruby/site_ruby/2.3.0/rubygems/core_ext 

But doesn't work. How to solve this error?

Thanks

EDIT:

gem list

*** LOCAL GEMS ***

cairo (1.12.8)
chunky_png (1.3.7)
compass-core (1.0.3)
compass-import-once (1.0.5)
execjs (2.7.0)
gettext (3.0.3)
locale (2.1.0)
multi_json (1.12.1)
rb-fsevent (0.9.7)
rdoc (3.9.4)
sass (3.4.22)
susy (2.2.12)
text (1.2.1)
nyan@nyan-Inspiron-7537:~$ susy -v
susy: command not found

Answer 1

You were mis-interpreting the error message:

LoadError on line ["55"] of ~/.rbenv/versions/2.3.1/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb: cannot load such file -- susy

The first part, LoadError , tells you what type of error you were running into; the documentation for LoadError states,

Raised when a file required (a Ruby script, extension library, ...) fails to load.

require 'this/file/does/not/exist'

raises the exception:

LoadError: no such file to load -- this/file/does/not/exist

The next part of the error message, on line ["55"] of ~/.rbenv/versions/2.3.1/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb: , tells you where the error occurred , that is, some piece of code called another piece of code which called another piece of code, eventually leading to line 55 of the file 'kernel_require.rb', which is part of the infrastructure of RubyGems. That line is, ultimately, what triggered the LoadError.

The final part of the error message, cannot load such file -- susy , gives you details about the problem; specifically, in the case of a LoadError such as this, it tells you what file it tried to (and failed) to load: 'susy'.

This all comes down to the fact that you had a directive in your gulp file, require: ['susy'] , but did not have the 'susy' gem installed. As you discovered, installing 'susy' (with gem install susy ) resolved the issue.

You also note that susy -v on the command line gave an error, but that's a red herring; the susy gem does not install any command line tools, only Ruby code.