package pack;

import org.hyperic.sigar.*;

public class NetworkData {
    public static void main(String[] args) {
   Sigar sigar = new Sigar();
    }

}

1 [main] DEBUG Sigar  - no libsigar-universal64-macosx.dylib in java.library.path
org.hyperic.sigar.SigarException: no libsigar-universal64-macosx.dylib in java.library.path
    at org.hyperic.sigar.Sigar.loadLibrary(Sigar.java:172)
    at org.hyperic.sigar.Sigar.<clinit>(Sigar.java:100)
    at pack.NetworkData.main(NetworkData.java:10)

# to find it later because you will need it ...
 cd ~/Downloads/

 # or whatever the latest one at the time of reading is ...
 curl https://netix.dl.sourceforge.net/project/sigar/sigar/1.6/hyperic-sigar-1.6.4.zip

 # unpack the package to the tmp dir
 sudo unzip -o /Users/phz/Downloads/hyperic-sigar-1.6.4.zip -d /tmp/

 # copy the libsigar-universal64-macosx.dylib to your class path dir
 sudo find /tmp/ -name libsigar-universal64-macosx.dylib
   -exec cp -v {} /Library/Java/Extensions/ ;

 # this cmd might be obsolete ...
 # copy the sigar.jar to your class path dir
 sudo find /tmp/ -name sigar*.jar
   -exec cp -v {} /Library/Java/Extensions/ ;

 # set you classpath dir, or add in ~/.bash_profile
 # or even better https://github.com/YordanGeorgiev/ysg-confs
 export CLASSPATH=$CLASSPATH:/Library/Java/Extensions

 # you should not see the error anymore
 cd $my_proj_dir ; sbt compile

 # neither here ..
 cd $my_project_dir ; clear ; sbt "test:testOnly *testClass"