I am trying to build my Sencha app at windows OS but getting this error. I am trying to use sencha command - sencha app build package, but build is failed. I already installed ant and compass
C:\xampp\htdocs\WhatsUnderMe>sencha app build package
Sencha Cmd v3.1.0.256
[INF]
[INF] init-plugin:
[INF]
[INF] init-plugin:
[INF] Invoking plugin (C:\xampp\htdocs\WhatsUnderMe\.sencha\app\plugin.xml) - supported targets: -before-app-build
[INF]
[INF] -before-app-build:
[INF] Invoking plugin (C:\xampp\htdocs\WhatsUnderMe\.sencha\app\plugin.xml) - supported targets: app-build
[INF]
[INF] cmd-root-plugin.init-properties:
[INF]
[INF] init-properties:
[INF]
[INF] init-sencha-command:
[INF]
[INF] init:
[INF]
[INF] -before-app-build:
[INF]
[INF] app-build-impl:
[INF]
[INF] package:
[INF]
[INF] -before-init-local:
[INF]
[INF] -init-local:
[INF]
[INF] -after-init-local:
[INF]
[INF] init-local:
[INF]
[INF] find-cmd:
[INF]
[INF] -before-init:
[INF]
[INF] -init:
[INF] Initializing Sencha Cmd ant environment
[INF] Adding antlib taskdef for com/sencha/command/compass/ant/antlib.xml
[INF]
[INF] -after-init:
[INF]
[INF] init:
[INF]
[INF] -before-build:
[INF]
[INF] sass:
[INF]
[INF] -before-sass:
[INF]
[INF] -sass:
[INF] executing compass using system installed ruby runtime
NoMethodError on line ["23"] of C: undefined method `empty?' for nil:NilClass
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/sass-3.1.7/lib/sass/engine.rb:293:in `_render'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/sass-3.1.7/lib/sass/engine.rb:240:in `render'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:140:in `block (2 leve
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:126:in `timed'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:139:in `block in comp
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/logger.rb:45:in `red'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:138:in `compile'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:118:in `compile_if_re
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:103:in `block (2 leve
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:101:in `each'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:101:in `block in run'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:126:in `timed'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/compiler.rb:100:in `run'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/commands/update_project.rb:45:in
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/commands/base.rb:18:in `execute'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/commands/project_base.rb:19:in `e
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/exec/sub_command_ui.rb:43:in `per
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/lib/compass/exec/sub_command_ui.rb:15:in `run
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/bin/compass:30:in `block in <top (required)>'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/bin/compass:44:in `call'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/gems/compass-0.12.2/bin/compass:44:in `<top (required)>'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/bin/compass:23:in `load'
C:/Users/Ido Tsuk/bin/Sencha/Cmd/3.1.0.256/extensions/sencha-compass/gems/bin/compass:23:in `<main>'
[ERR]
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.ExProcess: compass process exited with non-zero code : 1
[ERR]
[ERR] Total time: 0 seconds
[ERR]
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.BasicException: The following error occurred while executing this line:
[ERR] C:\xampp\htdocs\WhatsUnderMe\.sencha\app\build-impl.xml:223: com.sencha.exceptions.ExProcess: compass process exited with non-zero code
[ERR]
[ERR] Total time: 1 second
[ERR] com.sencha.exceptions.BasicException: The following error occurred while executing this line:
C:\xampp\htdocs\WhatsUnderMe\.sencha\app\build-impl.xml:223: com.sencha.exceptions.ExProcess: compass process exited with non-zero code : 1
What can i do to solve it?