In my bash script I redirected stdout and stderr to a logs file to prevent it from being printed in the terminal.
I set my script to exit on error occurrence using set -e switch.

Now, whenever any part of the code fails (exits with a non-zero exit code) the script stops being executed (as intended), but the trap part does not print my custom error message.

Additionally, when script stops execution, it doesn’t print a new line, resulting in the prompt staying in the same line as the last thing that was echoed by the bash script.

Bash script:

#!/usr/bin/env bash

###############################
#       env variables
###############################

#Environmental variables - paths to files storing installation logs and dependencies names to be installed
readonly LOGS_DIRECTORY="./logs/cherry-install/"
readonly LOGS_FILE=""$LOGS_DIRECTORY""$(date +%d-%m-%y_%H-%M-%S)".txt"
readonly ZYPPER_PACKAGES="./dependencies/zypper_packages.txt"
readonly ZYPPER_PATTERNS="./dependencies/zypper_patterns.txt"

###############################
#  non-installation functions
###############################

#Create logs directory
mkdir -p "$LOGS_DIRECTORY"

#Redirect stdout and stderr to logs file
exec 3>&1 1>>"$LOGS_FILE" 2>&1 
echo() (
   >&3 command echo "$@"
)

#Force script to exit on ERR occurence
set -e

#Error handler to call on ERR occurence and print an error message
error_handler(){
    echo -e " An error occured! See the installation logs file for specific information.n" 
}
trap 'error_handler' ERR
trap "echo -e 'nInstallation terminated manually!'; exit" SIGINT

#Universal function to read dependenies names from a file
read_file(){
    packages=()
    while IFS= read -r line || [[ -n "$line" ]]; do
        packages+=("$line")
    done < "$1"
}

###############################
#   installation functions
###############################

#Zypper repos refresh and package installation
install_zypper_packages(){
    read_file "$ZYPPER_PACKAGES"
    echo -n "[i] Refreshing zypper repositories: "
    zypper -n refresh
    echo 'OK'
    for line in "${packages[@]}"; do
        clean_line="${line//[^[:alnum:]-]/}"
        echo -n "[i] Installing "$clean_line": "
        zypper -n install -t package "$clean_line"
        echo 'OK'
    done
    echo ""
}

install_zypper_packages

Output when non-zero exit code is returned (script stops, but no trap message is printed).

lenovo:/scripts/Cherry-VM-Manager/environment-setup # ./cherry-install.sh
[i] Refreshing zypper repositories: OK
[i] Installing docker: OK
[i] Installing egvnjuiq: lenovo:/scripts/Cherry-VM-Manager/environment-setup #