fs/unix/tools: Throw error if umask output is invalid
fs/unix/tools: Throw error if umask output is invalid

keplerproject/luarocks,keplerproject/luarocks,luarocks/luarocks,tarantool/luarocks,luarocks/luarocks,keplerproject/luarocks,luarocks/luarocks,tarantool/luarocks,tarantool/luarocks,keplerproject/luarocks