pherkin: 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/pherkin - from package: libtest-bdd-cucumber-perl

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

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