git-clone-subset: 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 CentOS possible default full paths are:

/usr/bin/git-clone-subset - from package: git-tools

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