memccapable: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/memccapable - from package: libmemcached-tools

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