git-bloom-import-upstream: 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-bloom-import-upstream - from package: python-bloom

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