How to find output of shell command run by fastlane action?

Question

Sometimes it happens that a fastlane action throws an error like:
ERROR [2016-11-06 03:34:20.16]: Shell command exited with exit status 48 instead of 0.
I found troubleshooting difficult, as --verbose is not not verbose enough. By action I don't mean sh action, which is rather special case, but other fastlane actions eg create_keychain . The action create_keychain calls shell command security create-keychain and when it fails there is no clue what happened.

How do I find output of a shell command run by fastlane's action?
How do I find what shell command including all parameters is fastlane actually trying to run?

Answer 1

The output of the shell command is printed out by default when you use the sh action. Alternatively you can also run the shell command directly yourself using backticks (standard Ruby)

puts `ls`

Answer 2

The answer is that there is no such option at the moment, but it should be easy to add it. I have created git issue #6878 for it.