Compass 在 CSS 中输出回溯，而不是生成 CSS。我在 Windows 7 和 Ubuntu Linux 12.0 上得到了相同的结果，我在 Compass 0.12.2 和 0.11.1 上进行了测试，并在 Ruby 1.9.3p385 和 1.9.1P378 上进行了测试。
我的 config.rb 文件：
# Require any additional compass plugins here.
http_path = "/n4"
css_dir = "css"
sass_dir = "sass"
images_dir = "images"
javascripts_dir = "js"
# relative_assets = true
output_style = :compact #or :nested, :expanded, :compressed
line_comments = false
# Disable these for production (also when viewing in IE6; will cause unnecessary display errors)
# sass_options = {:debug_info => true}
CSS 文件的内容：
/*
Syntax error: Undefined mixin 'linear-gradient'.
on line 305 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass, in `linear-gradient'
from line 305 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass, in `button_style'
from line 590 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass
Backtrace:
C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass:305:in `linear-gradient'
C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass:305:in `button_style'
C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass:590
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:251:in `visit_mixin'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:98:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:266:in `block (3 levels) in visit_mixin'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:266:in `map'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:266:in `block (2 levels) in visit_mixin'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:119:in `with_environment'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:266:in `block in visit_mixin'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:68:in `perform_arguments'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:261:in `visit_mixin'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:98:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `block in visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `map'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:107:in `block in visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:119:in `with_environment'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:106:in `visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `block in visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:318:in `visit_rule'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:98:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `block in visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `map'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:53:in `visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:107:in `block in visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:119:in `with_environment'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:106:in `visit_children'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `block in visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:126:in `visit_root'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/base.rb:37:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:98:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/visitors/perform.rb:7:in `visit'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/tree/root_node.rb:20:in `render'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/engine.rb:315:in `_render'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/sass-3.2.5/lib/sass/engine.rb:262:in `render'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:140:in `block (2 levels) in compile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:126:in `timed'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:139:in `block in compile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/logger.rb:45:in `red'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:138:in `compile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:118:in `compile_if_required'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:103:in `block (2 levels) in run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:101:in `each'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:101:in `block in run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:126:in `timed'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/compiler.rb:100:in `run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass- 0.12.2/lib/compass/commands/watch_project.rb:147:in `recompile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/path.rb:73:in `call'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/path.rb:73:in `run_callback'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/path.rb:55:in `callback_action'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/path.rb:35:in `update'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/state/directory.rb:39:in `block in modified'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/state/directory.rb:37:in `each'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/state/directory.rb:37:in `modified'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/state/directory.rb:18:in `refresh'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/backends/polling.rb:17:in `block (2 levels) in run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/backends/polling.rb:17:in `each'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/backends/polling.rb:17:in `block in run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/backends/polling.rb:15:in `loop'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/backends/polling.rb:15:in `run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm/monitor.rb:26:in `run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/fssm-0.2.10/lib/fssm.rb:70:in `monitor'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/commands/watch_project.rb:87:in `perform'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/commands/base.rb:18:in `execute'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/commands/project_base.rb:19:in `execute'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/exec/sub_command_ui.rb:43:in `perform!'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/lib/compass/exec/sub_command_ui.rb:15:in `run!'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/bin/compass:30:in `block in <top (required)>'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/bin/compass:44:in `call'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/compass-0.12.2/bin/compass:44:in `<top (required)>'
C:/Ruby193/bin/compass:23:in `load'
C:/Ruby193/bin/compass:23:in `<main>'
*/
body:before {
white-space: pre;
font-family: monospace;
content: "Syntax error: Undefined mixin 'linear-gradient'.\A on line 305 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass, in `linear-gradient'\A from line 305 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass, in `button_style'\A from line 590 of C:/Users/bens/workspace/n4e/src/main/webapp/sass/screen.sass"; }