Add the plugin to your pom and run mvn compile, the default input directory is src/main/sass.
<build>
<plugins>
<plugin>
<groupId>org.tautua.maven.plugins</groupId>
<artifactId>sass-maven-plugin</artifactId>
<version>${LATEST}</version>
<executions>
<execution>
<id>compile-sass</id>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
You can be more precise by specifying which version of sass or what others gems to include.
<build>
<plugins>
<plugin>
<groupId>org.tautua.maven.plugins</groupId>
<artifactId>sass-maven-plugin</artifactId>
<version>${LATEST}</version>
<executions>
<execution>
<id>compile-sass</id>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
<configuration>
<rubygemsOptions>
<gems>
<gem>sass:3.4.22</gem>
<gem>susy:2.2.12</gem>
</gems>
</rubygemsOptions>
<sassOptions>
<input>src/test/sass</input>
<output>target/generated-test-sources/css</output>
<style>COMPRESSED</style>
</sassOptions>
</configuration>
</plugin>
</plugins>
</build>