fastarevcomp: 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 CentOS possible default full paths are:

/usr/bin/fastarevcomp - from package: exonerate

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

On Debian possible default full paths are:

/usr/bin/fastarevcomp - from package: exonerate

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

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