-e immediately exit when a command fails. No further commands are processed.
-o pipefail, if a series of piped commands fail, do NOt return the last commands returncode, but DO return the return code of the failing command in the pipeline series
-u, raise an error when an unset variable is used. Not using this results in an empty value being used and the script being executed differently without you knowing why.
-x, print each command before executing it. Actual arguments are expanded. So you see the command with the actual parameter values. This is printed in red in the buildx log output.