uicommon 2.15 compilation error

Hi team, I am trying to compile uicommon 2.15 module in my local with jdk-1.8 and getting below error.

[ERROR] Failed to execute goal de.saumya.mojo:gem-maven-plugin:1.0.0-rc4:exec (default) on project uicommons-scss: Execution default of goal de.saumya.mojo:gem-maven-plugin:1.0.0-rc4:exec failed: Java returned: 1 -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal de.saumya.mojo:gem-maven-plugin:1.0.0-rc4:exec (default) on project uicommons-scss: Execution default of goal de.saumya.mojo:gem-maven-plugin:1.0.0-rc4:exec failed: Java returned: 1
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)

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