On this page
there are instructions on how to use nightly with its own profile so both release and nightly can be run by choice, one or the other.
Here are the instructions. The Terminal Command Line code suggested FAILS. No such file or directory.
How do I install Firefox Nightly alongside Firefox Release?
Now you’ll need to create a dedicated profile for your Nightly, different from your Firefox stable one to avoid trouble.
To do that, you need to open your terminal and run Nightly, only for the first time by running the following command:
/Applications/FirefoxNightly.app/Contents/MacOS/firefox -P --no-remote
This will open the profile manager. Here, create a new profile with the name you want, and uncheck the checkbox saying “Use the selected profile without asking at startup”, so that at every Firefox start you can choose the profile you want and corresponding to either your Nightly or Stable Firefox.
I noticed that the actual name of the app container has a space between Firefox and Nightly. I tried editing the command to insert the space. It made no difference.
Please help me by providing a terminal command line that will actually work. Or do I need to add sudo ahead of the command line? I believe I am at the root of my user directory tree.
Here is the screen text from terminal:
Macintosh:~ norm$ /Applications/FirefoxNightly.app/Contents/MacOS/firefox -P --no-remote
-bash: /Applications/Firefox: No such file or directory