sigcleave: 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 Debian possible default full paths are:

/usr/bin/sigcleave - from package: emboss

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

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