loginfo-handler: 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

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/lib/python2.6/site-packages/viewvc/bin/loginfo-handler - from package: viewvc

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/share/gforge/www/scm/viewvc/bin/loginfo-handler - from package: gforge-web-apache2
/usr/lib/viewvc/bin/loginfo-handler - from package: viewvc-query

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