Merge pull request #24 from cs169/187057751-update-INSTALL_SNAPCON

update INSTALL_SNAPCON.md

Author: warrenlet

INSTALL_SNAPCON.md

@@ -18,6 +18,19 @@ The recommended setup steps are as follows:
     1. Other features will require more environment variables. See [Environment Variables](#environment-variables) and [INSTALL.md#configuration](INSTALL.md#configuration) for all the environment variables that may be set.
 1. Run `rake db:setup` (this command and all following commands may need to prefixed with `bundle exec`) to initialize the database.
 
+## Setting Environment Variables for macOS
+
+For developers using macOS, it's necessary to set an environment variable to prevent issues related to forking processes. Before starting the application, please set `OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES` by following these steps:
+
+### For Temporary Use in the Current Terminal Session
+
+Execute the following command in your terminal:
+
+```
+export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
+```
+This will set the environment variable for the duration of your current terminal session. You'll need to run this command each time you open a new terminal window.
+
 ## Local Deployment
 
 To run Snap!Con, using [Overmind](https://github.com/DarthSim/overmind) or [Foreman](https://github.com/ddollar/foreman) is recommended. Since a release command is run which automatically performs migrations, it is necessary to flag the `release` command as able to be exited without closing all other processes. The Rails server may be run via the typical `rails server` command, but do note that no jobs will be run.