There's definitely something wrong with your machine or settings. Our build time is of course highly dependent on number of cores (our build will use them all), their speed, and available memory, but the range for a rebuild on reasonably modern machines tends to be 5 - 20 minutes. I believe all developers at LabKey using Macs (MacBook Pro laptops) are in that range.

Please provide more information. What is your machine configuration (model name, number of cores, speed, RAM)? Please reboot and issue an "ant rebuild" from the command line (to eliminate variability introduced by your IDE) and report the time it takes. If it's still slow, can you tell which parts are taking a long time?

Of course a full rebuild is rarely needed during incremental development. "ant build" or "ant <module name>" should be sufficient in most cases. And you can configure incremental IntelliJ builds and hot-swapping for even faster incremental development (with some caveats). Also, the -DdevMode=true flag and gwt-user-override environment variable can be helpful. Our documentation explains all of these options:
https://www.labkey.org/wiki/home/Documentation/page.view?name=build

In your case, though, you have an underlying configuration problem that needs to be addressed.

Adam