After stopping the server, suddenly I can't run middleman anymore

I’m so upset.

I was running along, building a site, the middleman server was serving things up.

Then I shut it down to check everything into github, and now, anytime I run bundle exec middleman s, it gives an error:

$ bundle exec middleman s
bundler: failed to load command: middleman (/usr/local/bin/middleman)
LoadError: cannot load such file -- less
  /usr/local/lib/ruby/gems/2.4.0/gems/tilt-2.0.7/lib/tilt/less.rb:2:in `require'

So I install the less gem.

Then it tells me it needs “therubyracer” gem as well.

Why did it run the first time, but not the second?

Why aren’t these things included in the installation Gemfile?

It looks similar to what I encountered with other Ruby software after installing newer Ruby version with rvm for use with Middleman. So, it is possible that you recently switched/updated Ruby version, knowingly or not, and hence all gems might need to be installed for new Ruby version.

As to why this isn’t handled automatically by Middleman or Bundler, I have no idea.

I has received this error too… I downloaded fontawesome and its has css, less and scss folder inside, I delete less and scss folders and run server again.

When server is started, this read all folders an files, and found .scss and .less files, and dont know what do with theses files. Then middleman show a info to install less…