pod 集成不成功
[!] CDN: trunk Repo update failed - 18 error(s):
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.1.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.2.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.3.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.4.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.5.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.7.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.8.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.1.9.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.2.0.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/1.2.1.P/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.2.5/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.2.8/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.2.9/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.3.0/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.3.1/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.3.2/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.3.3/UMCommon.podspec.json Response: Couldn't connect to server
CDN: trunk URL couldn't be downloaded: https://cdn.cocoapods.org/Specs/b/c/6/UMCommon/7.3.5/UMCommon.podspec.json Response: Couldn't connect to server
集成总是报错,要怎么解决?