bsdiff: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/bsdiff - from package: bsdiff

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/bsdiff - from package: bsdiff

You may install the required package with command apt-get install {package}

Error in other languages:
bsdiff: bevel nie gevind nie
bsdiff: comandă negăsită
bsdiff: comando não encontrado
bsdiff: commande introuvable
bsdiff: command not found
bsdiff: käsku ei ole
bsdiff: không tìm thấy lệnh
bsdiff: komanda nerasta
bsdiff: Kommando nicht gefunden.
bsdiff: kommandot finns inte
bsdiff: komut yok
bsdiff: nie znaleziono polecenia
bsdiff: níor aimsíodh an t-ordú
bsdiff: no se encontró la orden
bsdiff: no s'ha trobat l'ordre
bsdiff: opdracht niet gevonden
bsdiff: parancs nem található
bsdiff: perintah tidak ditemukan
bsdiff: príkaz nenájdený
bsdiff: příkaz nenalezen
bsdiff: команда не найдена
bsdiff: командата не е открита
bsdiff: 命令找不到
bsdiff: コマンドが見つかりません