pmccabe: 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/pmccabe - from package: pmccabe

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