I'm having an error regarding my Flutter application. When I run the "flutter run" script in terminal, I'm getting the following error from Cocoapods: "Error output from CocoaPods: Searching for inspections failed: undefined method `map' for nil:NilClass" (as seen also by the attached picture). 
How do I go about solving this issue?
Are you using Apple M1? I had this issue as well and after some research I find that it might be something to do with Rosetta. You can refer to Running CocoaPods on Apple Silicon (M1).
I managed to solve this issue on my MacBook Air M1 by typing this in the terminal:
sudo arch -x86_64 gem install ffi
I was trying to run pod install command in ios folder.
@boonyongyang solution is necessary but it seemed that I had 2 ffi's installed, so I had to also run it with arch -x86_64 command
sudo arch -x86_64 gem install ffi
# go to ios folder then run
arch -x86_64 pod install
I struggled for many hours to figure this out, none of the solutions from Stack Overflow worked. Finally, I found this note in official Flutter documentation:
This problem arises on computers running on M1 chip. Just run the following code snippet in your terminal and everything works fine.
sudo gem uninstall ffi && sudo gem install ffi -- --enable-libffi-alloc
On my MacBook M1 that issue came up when I accidentally added an blank line to the pubspec.yaml file. Deleting the line solved the issue (it looks like you can't have two empty lines one after another).