Looking for a styles.scss in a wrong place

General
1

I don’t what did I changed but my project is not compiling. Seems to be looking for a themes\icons\styles.scss , why Vaadin is looking for a SCSS here?
I am using Netbeans, Vaadin 8.4.0, console output:

Theme "VAADIN\themes\mytheme" updated

--- vaadin-maven-plugin:8.4.0:compile-theme (default) @ choferes-ui ---
Updating theme VAADIN\themes\icons
D:\NetBeansProjects\choferes\choferes-ui\src\main\webapp\VAADIN\themes\icons\styles.scss could not be read!
Compiling theme "VAADIN\themes\icons" failed
org.codehaus.mojo.gwt.shell.JavaCommandException: Command [[
C:\Program Files\Java\jdk1.8\jre\bin\java -Xmx1G com.vaadin.sass.SassCompiler D:\NetBeansProjects\choferes\choferes-ui\src\main\webapp\VAADIN\themes\icons\styles.scss D:\NetBeansProjects\choferes\choferes-ui\src\main\webapp\VAADIN\themes\icons\styles.css
]] failed with status 2
    at org.codehaus.mojo.gwt.shell.JavaCommand.execute (JavaCommand.java:330)
    at com.vaadin.integration.maven.CompileThemeMojo.processTheme (CompileThemeMojo.java:65)
    at com.vaadin.integration.maven.AbstractThemeMojo.doExecute (AbstractThemeMojo.java:43)
    at org.codehaus.mojo.gwt.shell.AbstractGwtShellMojo.execute (AbstractGwtShellMojo.java:182)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
2

build success if I move the folder from \themes\icons to \themes\mytheme\icons

But I would like to keep the schema:

\themes
--\icons (commons for all themes)
--\mytheme
-- --\icons (specific of the theme)
--\dark
-- --\icons (specific of the theme)
3

I think you will need to have something like

\themes
--\parent-theme
-- --\icons (common for all themes)
--\mytheme (inherits parent-theme)
-- --\icons (specific of the theme
--\dark (inherits parent-theme)
-- --\icons (specific of the theme
4

I would try to make that inheritance but that doesn’t explain Vaadin’s compiler behaviour.
I have a similar setup in a project with Vaadin 7.7.13 and it works fine