You are missing: > E If set, any trap on ERR is inherited by shell functions, command substitutions, and commands executed in a subshell environment. The

You are missing: > E If set, any trap on ERR is inherited by shell functions, command substitutions, and commands executed in a subshell environment. The ERR trap is normally not inherited in such cases. set -eu is at least 30 years old. Not sure whether it makes sense to rewrite established code.