# Revision history [back]

Catkin gets the number of jobs from the ROS_PARALLEL_JOBS environment variable. If you want to use n jobs, you can do the following before building a catkin project in catkin version 0.5.63:

export ROS_PARALLEL_JOBS=n


This is currently considered a compatibility bug, since for rosbuild, this should be:

export ROS_PARALLEL_JOBS=-jn


In the future versions of catkin, I believe the second option above will be the correct one.

Catkin gets the number of jobs from the ROS_PARALLEL_JOBS environment variable. If you want to use n jobs, you can do the following before building a catkin project in catkin version 0.5.63:

export ROS_PARALLEL_JOBS=n


This is currently considered a compatibility bug, since for rosbuild, this should be:

export ROS_PARALLEL_JOBS=-jn


In the future versions of catkin, I believe the second option above will be the correct one.one. See this ticket here: https://github.com/ros/catkin/issues/335

If you don't specify the numbers of jobs explicitly with -jn for n jobs when calling make or catkin_make, Catkin gets the number of jobs from the ROS_PARALLEL_JOBS environment variable. From the catkin_make help:

  -j [JOBS], --jobs [JOBS]
Specifies the number of jobs (commands) to run
simultaneously. Defaults to the environment variable
ROS_PARALLEL_JOBS and falls back to the number of CPU
cores.


If you want to use n jobs, jobs by default, you can do the following before building a catkin project in catkin version 0.5.63:

export ROS_PARALLEL_JOBS=n


This is currently considered a compatibility bug, since for rosbuild, this should be:

export ROS_PARALLEL_JOBS=-jn


In the future versions of catkin, I believe the second option above will be the correct one. See this ticket here: https://github.com/ros/catkin/issues/335