I created this web app: https://github.com/ZGIS/malawi_atlas_public
I can watch it using "sencha app watch", but when I build the app with "sencha app build" I receive the error message below.

Do you have any idea what the problem is?




Code:
$ sencha app build
Sencha Cmd v6.6.0.13
[INF] Using GPL version of Ext JS version 6.2.0.981 from /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/ext.
[INF] The implications of using GPL version can be found here (http://www.sencha.com/products/extjs/licensing).
[INF] Processing Build Descriptor : default (production environment)
[INF] Loading compiler context
[INF] Loading app json manifest...
[INF] Processing data with CmdJavascriptCompressor
[INF] JavaScript input level is NEXT and output level is ES5
[WRN] C1005: Closure Compiler Warning (Parse error. extra visibility tag) -- compression-input:102090:7
[INF] Writing concatenated output to file /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas/app.js
[INF] merging 233 input resources into /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas/resources
[INF] merged 233 resources into /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas/resources
[INF] merging 21 input resources into /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas
[INF] merged 21 resources into /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas
[INF] Writing content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/bootstrap.json
[INF] Writing content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/bootstrap.js
[INF] writing sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/MalawiAtlas-example.scss.tmp
[INF] writing sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/config.rb
[WRN] Use of 'require()' will be deprecated: /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/ext/classic/theme-neutral/sass/etc/mixins/font-icon.scss:1
[WRN] Use @import instead
[LOG] Fashion build starting for /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/MalawiAtlas-example.scss
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-checked.png
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-unchecked.png
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-group-checked.png
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-menu-parent-left.png
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-scroll-top.png
[WRN] @theme-background-image: Theme image not found: images/menu/default-menubar-scroll-bottom.png
[WRN] @theme-background-image: Theme image not found: images/tab/tab-navigation-close.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-scroll-left.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-scroll-right.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-scroll-top.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-scroll-bottom.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-more.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-more-left.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-plain-scroll-left.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-plain-scroll-right.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-plain-scroll-top.png
[WRN] @theme-background-image: Theme image not found: images/tab-bar/navigation-plain-scroll-bottom.png
[LOG] Fashion build complete for /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/MalawiAtlas-example.scss
[LOG] Fashion build completed in 1.954 sec.
[INF] Capturing theme image
[INF] Capture complete
[INF] Slicing images...
[INF] Slicing complete - generated 320 images
[INF] Writing content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/bootstrap.json
[INF] Writing content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/slicer-temp/bootstrap.js
[INF] writing sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/MalawiAtlas-all.scss.tmp
[INF] appending sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/MalawiAtlas-all.scss.tmp
[INF] appending sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/MalawiAtlas-all.scss.tmp
[INF] writing sass content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/config.rb
[INF] Writing content to /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/production/MalawiAtlas/app.json
[WRN] Use of 'require()' will be deprecated: /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/ext/classic/theme-neutral/sass/etc/mixins/font-icon.scss:1
[WRN] Use @import instead
[LOG] Fashion build starting for /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/MalawiAtlas-all.scss
[ERR] unknown definition for mixin named extjs-tab-panel-ui : /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/sass/src/view/main/Main.scss:4
[LOG] Build error for /home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/build/temp/production/MalawiAtlas/sass/MalawiAtlas-all.scss
{ Error: Sass compilation encountered 1 error(s)
    at Object.raise (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/export/Base.js:131:17)
    at Transpiler.transpile (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/Transpiler.js:1549:21)
    at Context.convert (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/Context.js:42:34)
    at /home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/Builder.js:147:45
    at SassFile.fireReady (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:426:17)
    at /home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:398:28
    at SassFile.fireReady (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:426:17)
    at /home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:398:28
    at SassFile.fireReady (/home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:426:17)
    at /home/peterpan/bin/Sencha/Cmd/6.6.0.13/js/node_modules/fashion/src/SassFile.js:398:28 '$isFashionError': true }
[ERR]
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.ExBuild: Fashion build exited with code : 1
[ERR]   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImp
[ERR] l.java:62)
[ERR]
[ERR] Total time: 20 seconds

[ERR] /home/peterpan/bin/Sencha/Cmd/6.6.0.13/plugin.xml:333: The following error occurred while executing this line:
/home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/.sencha/app/build-impl.xml:291: The following error occurred while executing this line:
/home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/.sencha/app/sass-impl.xml:205: The following error occurred while executing this line:
/home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/.sencha/app/sass-impl.xml:240: com.sencha.exceptions.ExBuild: Fashion build exited with code : 1
[ERR] A log is available in the file "/home/peterpan/projects/Malawi_Atlas/Code/malawi_atlas/sencha-error-20180712-3.log"