Rebooted my system.
JAVA_HOME seems not to be causing troubles anymore, instead I'm getting the following error:
Execution failed for task ':makeStart'.
Could not resolve all dependencies for configuration ':minecraftDeps'.
Could not resolve com.typesafe.akka:akka-actor_2.11:2.3.3.
Required by:
com.yourname.modid:forge-1.8-11.14.1.1334-src:1.0
Could not HEAD 'http://repo1.maven.org/maven2/com/typesafe/akka/akka-actor_2.11/2.3.3/akka-actor_2.11-2.3.3.pom
Connection reset
I'm getting a 403 error for this URL.