If you’re using Vagrant to run os/161, you can still use your favorite GUI (and other) tools to edit sourcecode. One common approach to this is to place the sourcecode in the …/vagrant/shared directory. That way, all the sourcefiles are visible from both the host OS for editing with GUI tools etc. AND from the guest OS (vagrant) for building and running os161.
If you use this approach, note that if you git clone the sourcecode (ASST0 section 3.1) in the shared directory, the base of your sourcecode in Vagrant will be $HOME/shared/os161. However, the default install location (where the files are placed when you type “bmake install”) for the compiled files, per the “configure” file discussed in ASST0 section 3.2, is $HOME/os161/root. That is, there will be two os161 directories. You can, of course, reconfigure the install location to combine these or do something else.
tl;dr Have your cake and eat it too