我正在 Ubuntu 16.04 上构建 Open Air Interface。正如 Open Air Interface Wiki 所解释的那样，我使用了以下命令：
source oaienv
cd cmake_targets
./build_oai -I -w USRP
出现以下错误：
Will install external packages
Setting hardware to: OAI_USRP
CMAKE_CMD=cmake ..
RF HW set to OAI_USRP
Flags for Deadline scheduler: False
Flags for CPU Affinity: False
2. Setting the OAI PATHS ...
OPENAIR_DIR = /home/foo/Downloads/openairinterface5g
FreeDiameter prefix not found, install freeDiameter if EPC, HSS
Installing packages
[sudo] password for foo:
Ign:1 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial InRelease
Hit:2 http://it.archive.ubuntu.com/ubuntu xenial InRelease
Get:3 http://it.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Ign:4 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial Release
Get:5 http://security.ubuntu.com/ubuntu xenial-security InRelease [109 kB]
Get:6 http://it.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]
Ign:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Get:9 http://it.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [902 kB]
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Get:13 http://it.archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [795 kB]
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Get:15 http://it.archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [320 kB]
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Get:17 http://it.archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [227 kB]
Get:18 http://it.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [721 kB]
Get:19 http://it.archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [660 kB]
Ign:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
Get:20 http://it.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [249 kB]
Get:21 http://it.archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [348 kB]
Get:22 http://it.archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,968 B]
Get:23 http://it.archive.ubuntu.com/ubuntu xenial-updates/multiverse DEP-11 64x64 Icons [14.3 kB]
Get:24 http://it.archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,328 B]
Get:25 http://it.archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [5,104 B]
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Ign:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Ign:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Ign:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Err:7 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 Packages
404 Not Found
Ign:8 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en_GB
Ign:12 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main Translation-en
Ign:14 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:16 http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial/main DEP-11 64x64 Icons
Fetched 4,575 kB in 7s (634 kB/s)
Reading package lists... Done
W: The repository 'http://ppa.launchpad.net/chris-lea/zeromq/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://ppa.launchpad.net/chris-lea/zeromq/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
build have failed
我该如何解决这个问题？
谢谢
答案1
使用以下命令解决删除 ppa 的问题：
sudo add-apt-get --remove ppa:chris-lea/zeromq
这样，脚本apt-get update中包含的命令build_oai就不会抛出错误，并且构建可以顺利进行。
谢谢