subunit-diff: 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/subunit-diff - from package: subunit

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

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