How to set heap size for sbt?

Question

I am using SBT 0.12.0. I have read other answers on stack overflow and followed them, however none of them helps, for example:

• create ForkRun clas

Answer 1

I have found the solution. No matter how you specify JVM heap size, it will never work because SBT executable already has it overridden.

There is a line in SBT executable which says:

. /usr/share/sbt/sbt-launch-lib.bash

So I edited the file:

  # run sbt
  execRunner "$java_cmd" \
    ${SBT_OPTS:-$default_sbt_opts} \
-   $(get_mem_opts $sbt_mem) \
    ${java_opts} \
    ${java_args[@]} \
    -jar "$sbt_jar" \
    "${sbt_commands[@]}" \
    "${residual_args[@]}"

Remove the - line.

Now when you run SBT, it will no longer override your JVM heap size settings. You can specify heap size settings using @Noan's answer.

Or alternatively:

sbt -J-Xmx4G -J-Xms4G