synccompare: 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/synccompare - from package: syncevolution-common

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

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