Oh I really have many files to be resolved. I’ll read the manual and finish them ~12 hours later.
$ pacdiff -s
==> pacsave file found for /usr/share/icons/default/index.theme
:: (V)iew, (M)erge, (S)kip, (R)emove pacsave, (O)verwrite with pacsave, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/hosts
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/passwd
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/shells
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/locale.gen
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/default/grub
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/pamac.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/mkinitcpio.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/ssh/ssh_config
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/ssh/sshd_config
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/pacman.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/makepkg.conf.d/fortran.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/makepkg.conf.d/rust.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/pacman-mirrors.conf
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/pam.d/sddm
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s
==> pacnew file found for /etc/sudoers
:: (V)iew, (M)erge, (S)kip, (R)emove pacnew, (O)verwrite with pacnew, (Q)uit: [v/m/s/r/o/q] s