I'm trying to do the theme-tutorial in the documentation, but
after updating extjs to 4.2.1 and the cmd to 3.1.2.342 it got an BUILD FAILD err.
Befor I had no problem too create and build projects form the cmd.

Code:
airrob:extjs galien$ ../../bin/Sencha/Cmd/3.1.2.342/sencha -sdk ext generate app ThemeApp ../extjs_tryouts/theme-demo-app
Sencha Cmd v3.1.2.342
[INF] 
[INF] init-plugin:
[INF] 
[INF] cmd-root-plugin.init-properties:
[INF] 
[INF] init-properties:
[INF] 
[INF] init-sencha-command:
[INF] 
[INF] init:
[INF] 
[INF] before-upgrade:
[INF] 
[INF] generate-app-impl:
[INF] 
[INF] generate-starter-app:
[INF]     [mkdir] Created dir: /Users/galien/Sites/extjs_tryouts/theme-demo-app/resources
[INF]     [mkdir] Created dir: /Users/galien/Sites/extjs_tryouts/theme-demo-app/overrides
[INF]     [mkdir] Created dir: /Users/galien/Sites/extjs_tryouts/theme-demo-app/sass/src
[INF]     [mkdir] Created dir: /Users/galien/Sites/extjs_tryouts/theme-demo-app/sass/var
[INF]     [mkdir] Created dir: /Users/galien/Sites/extjs_tryouts/theme-demo-app/sass/etc
[INF] [x-property-file] Updating property file: /Users/galien/Sites/extjs_tryouts/theme-demo-app/.sencha/app/sencha.cfg
[INF] 
[INF] after-upgrade:
[ERR] 
[ERR] BUILD FAILED
[ERR] java.lang.NullPointerException
[ERR] 
[ERR] Total time: 2 seconds
[ERR] com.sencha.exceptions.BasicException
then I try to build and to create a theme with err NULL:

Code:
airrob:extjs galien$ cd ../extjs_tryouts/theme-demo-app


airrob:theme-demo-app galien$ ls
Readme.md	app.js		bootstrap.css	build.xml	overrides	resources
app		app.json	bootstrap.js	index.html	packages	sass
airrob:theme-demo-app galien$ ../../../bin/Sencha/Cmd/3.1.2.342/sencha app build
[ERR] null
     at com.sencha.command.environment.WorkspaceEnvironment.extractPackage(WorkspaceEnvironment.java:176)
     at com.sencha.command.environment.WorkspaceEnvironment.getPackageEnvironment(WorkspaceEnvironment.java:196)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageEnvironment(AppOrPackageEnvironment.java:245)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageEnvironments(AppOrPackageEnvironment.java:255)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageNames(AppOrPackageEnvironment.java:266)
     at com.sencha.command.environment.AppEnvironment.<init>(AppEnvironment.java:54)
     at com.sencha.command.environment.BuildEnvironment.load(BuildEnvironment.java:193)
     at com.sencha.command.Sencha.loadBuildEnvironment(Sencha.java:374)
     at com.sencha.command.Sencha.main(Sencha.java:127)


airrob:theme-demo-app galien$ ../../../bin/Sencha/Cmd/3.1.2.342/sencha generate theme my-custom-theme
[ERR] null
     at com.sencha.command.environment.WorkspaceEnvironment.extractPackage(WorkspaceEnvironment.java:176)
     at com.sencha.command.environment.WorkspaceEnvironment.getPackageEnvironment(WorkspaceEnvironment.java:196)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageEnvironment(AppOrPackageEnvironment.java:245)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageEnvironments(AppOrPackageEnvironment.java:255)
     at com.sencha.command.environment.AppOrPackageEnvironment.getThemePackageNames(AppOrPackageEnvironment.java:266)
     at com.sencha.command.environment.AppEnvironment.<init>(AppEnvironment.java:54)
     at com.sencha.command.environment.BuildEnvironment.load(BuildEnvironment.java:193)
     at com.sencha.command.Sencha.loadBuildEnvironment(Sencha.java:374)
     at com.sencha.command.Sencha.main(Sencha.java:127)
someone have a suggestion?

greetings Rob