less - 预期 ')' 得到 '.' ！！！如何检测有错误的文件？

Question

我最近升级less到1.3.3v开始遇到这个错误

 expected ')' got '.'

在少到 css 编译期间...

这是错误跟踪

在错误 (/.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js:198:15) 在期望 (/.rvm/ gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js:190:13）在对象。(/.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js:884:25) 在 $ (/.rvm/gems/ ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js:133:24) 在 Object.primary (/.rvm/gems/ruby-1.9.3 -p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js:527:32) 在 $ (/.rvm/gems/ruby-1.9.3-p286/gems/less- 2.3.2/lib/less/js/lib/less/parser.js:133:24) 在 Object.block (/.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib /less/js/lib/less/parser.js:1121:42) 在 $ (/.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/ less/parser.js:133:24) 在 Object.ruleset (/.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/js/lib/less/parser.js :1144:block in to_css' /.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/java_script/v8_context.rb:90:in阻塞在 do_lock' /.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/java_script/v8_context.rb:88:in do_lock' /.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/java_script/v8_context.rb:60:inlock' /.rvm/gems/ruby-1.9 .3-p286/gems/less-2.3.2/lib/less/java_script/v8_context.rb:30:in exec' /.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/lib/less/java_script.rb:26:inexec' /.rvm/gems/ruby-1.9.3-p286/gems/less-2.3.2/ lib/less/parser.rb:103:in `to_css'

猜猜它的一些语法错误......我的问题是如何检测文件和错误的行号？？？不知道怎么调试？？？有什么建议么 ？？？？

PS：升级前没遇到过