gcm-inspect: 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/gcm-inspect - from package: gnome-color-manager

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