CreateProcess error=206, The filename, or extension is too long

I finally managed to solve it:

Turns out birt, together with its dependencies, was simply adding too many libraries and the classpath became too long for windows command to handle. Furthermore, birt libraries have stupidly long names.

Solved it using this dependency (I only needed the runtime), I created the lib and birt directories and placed the jar there myself:

<dependency>
    <groupId>org.eclipse.birt.runtime</groupId>
    <artifactId>org.eclipse.birt.runtime</artifactId>
    <version>4.4.1</version>
    <scope>system</scope>
    <systemPath>${basedir}/lib/birt/birt.runtime-4.4.1.jar</systemPath>
</dependency>