在生产中预编译资产时，我一直面临NoMethodError: undefined method start_with?' for nil:NilClass错误。
这似乎是一个问题，uglifier我正在使用以下宝石：
导轨 (5.2.2)
丑化者 (4.1.9)
链轮导轨 (3.2.1)
therubyracer (0.12.3)
日志跟踪：
** Invoke assets:precompile (first_time)
** Invoke assets:environment (first_time)
** Execute assets:environment
** Invoke environment (first_time)
** Execute environment
** Invoke yarn:install (first_time)
** Execute yarn:install
yarn install v1.13.0
[1/4] Resolving packages...
success Already up-to-date.
Done in 0.36s.
** Execute assets:precompile
rake aborted!
NoMethodError: undefined method `start_with?' for nil:NilClass
/usr/lib64/ruby/gems/2.4.0/gems/uglifier-4.1.9/lib/uglifier.rb:225:in `error_message'
/usr/lib64/ruby/gems/2.4.0/gems/uglifier-4.1.9/lib/uglifier.rb:234:in `parse_result'
/usr/lib64/ruby/gems/2.4.0/gems/uglifier-4.1.9/lib/uglifier.rb:216:in `run_uglifyjs'
/usr/lib64/ruby/gems/2.4.0/gems/uglifier-4.1.9/lib/uglifier.rb:168:in `compile'
/usr/lib64/ruby/gems/2.4.0/gems/sprockets-3.7.1/lib/sprockets/compressing.rb:65:in `block in js_compressor='
/usr/lib64/ruby/gems/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy_proc_processor.rb:31:in `call'
我检查了此处报告的类似问题，但添加config.assets.js_compressor = Uglifier.new(harmony: true, compress: { unused: false })到config/environments/production.rb并没有解决问题。
任何解决该问题的线索将不胜感激。谢谢！