/usr/bin/scss --no-cache --update sam-plugins.scss:sam-plugins.css /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/lib/sass/version.rb:49:in `read': No such file or directory @ rb_sysopen - /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/VERSION (Errno::ENOENT) from /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/lib/sass/version.rb:49:in `version' from /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/lib/sass/version.rb:121:in `<module:Sass>' from /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/lib/sass/version.rb:4:in `<top (required)>' from /usr/lib64/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require' from /usr/lib64/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require' from /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/lib/sass.rb:4:in `<top (required)>' from /usr/lib64/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require' from /usr/lib64/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require' from /usr/lib64/ruby/gems/2.4.0/gems/sass-3.5.3/bin/scss:6:in `<top (required)>' from /usr/bin/scss:9:in `load' from /usr/bin/scss:9:in `<main>'
*** Bug 638298 has been marked as a duplicate of this bug. ***
I can't reproduce this with 3.5.4, but this may have been causes by issues with installing the 3.4 and 3.5 slots at the same time. Can you try with sass 3.5.4?