這段時間在調試ROS數據融合相關問題，在下載sudo apt-get install ros-kinetic-bfl包是提示
Err:1 http://packages.ros.org/ros/ubuntu xenial/main amd64 ros-kinetic-bfl amd64 0.7.0-2xenial-20180809-134309-0800
404 Not Found [IP: 64.50.233.100 80]
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-kinetic-bfl/ros-kinetic-bfl_0.7.0-2xenial-20180809-134309-0800_amd64.deb 404 Not Found [IP: 64.50.233.100 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
這是找不到amd64 ros-kinetic-bfl amd64 0.7.0-2xenial-20180809-134309-0800這個包,後來去官方網站看到是，包前幾天是做過更新的
[PARENTDIR] Parent Directory -
[ ] ros-kinetic-bfl_0.7.0-2xenial-20190607-165528-0800_amd64.deb 2019-06-07 21:03 205K
[ ] ros-kinetic-bfl_0.7.0-2xenial-20190607-173908-0800_i386.deb 2019-06-07 21:48 216K
[ ] ros-kinetic-bfl_0.7.0-2xenial-20190608-234544-0800_armhf.deb 2019-06-09 04:12 182K
[ ] ros-kinetic-bfl_0.7.0-2xenial-20190609-001148-0800_arm64.deb 2019-06-09 04:39 190K
[ ] ros-kinetic-bfl_0.7.0-2xenial.debian.tar.xz 2019-05-30 03:58 8.2K
[TXT] ros-kinetic-bfl_0.7.0-2xenial.dsc 2019-05-30 03:58 948
[ ] ros-kinetic-bfl_0.7.0.orig.tar.gz 2019-05-30 03:58 257K
然後我 sudo apt-get update 下我的Ubuntu，提示下面錯誤信息：
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://packages.ros.org/ros/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
W: Failed to fetch http://packages.ros.org/ros/ubuntu/dists/xenial/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
W: Some index files failed to download. They have been ignored, or old ones used instead.
做了幾次更新還是同一樣的錯誤，提示我簽名未更新的，難道不是系統自己更新索引的麼....
好吧，由於任務要緊，不能坐以待斃，我想，ROS官方應該有更新，找到ROS官方安裝ros的例程，重新更新下key，http://wiki.ros.org/kinetic/Installation/Ubuntu，我的是kinetic的。
sudo apt-key adv --keyserver'hkp：//keyserver.ubuntu.com:80'-recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
再 sudo apt-get update 就好了，後面安裝bfl也是沒問題的。