由于GPG错误无法更新我的系统Clearsigned文件无效，得到’NODATA’
我无法更新……
我一直试图解决这个问题一段时间……我发现的唯一方法是重新安装Ubuntu …
sudo apt-get update -o Debug::Acquire::http=true 0% [Connecting to mirror.bytemark.co.uk (212.110.161.69)] [Connecting to archivGET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: archive.canonical.com Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Mon, 02 Jun 2014 21:50:58 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) 0% [Connecting to mirror.bytemark.co.uk (212.110.161.69)] [Waiting for headers]GET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: mirror.bytemark.co.uk Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Sat, 07 Jun 2014 00:11:36 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: extras.ubuntu.com Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Sat, 07 Jun 2014 00:19:18 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /appgrid/stable/ubuntu/dists/trusty/InRelease HTTP/1.1 Host: ppa.launchpad.net Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Thu, 05 Jun 2014 14:53:42 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /torproject.org/dists/trusty/InRelease HTTP/1.1 Host: deb.torproject.org Cache-Control: max-age=0 Accept: text/* If-Modified-Since: Fri, 30 May 2014 11:28:02 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) HTTP/1.1 200 OK Content-Type: text/html; charset=UTF-8 Content-Length: 213 Date: Sat, 07 Jun 2014 00:20:52 GMT Server: Apache/2.2.22 (Ubuntu) Vary: Accept-Encoding Get:1 http://extras.ubuntu.com trusty InRelease [213 B] 94% [1 InRelease gpgv 213 B] [Waiting for headers] [Waiting for headers] [WaitiSplitting up /var/lib/apt/lists/partial/extras.ubuntu.com_ubuntu_dists_trusty_InRIgn http://extras.ubuntu.com trusty InRelease E: GPG error: http://extras.ubuntu.com trusty InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?) superuser@dude-X202E:~$ sudo apt-get update -o Debug::Acquire::http=true 0% [Working]GET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: archive.canonical.com Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Mon, 02 Jun 2014 21:50:58 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: extras.ubuntu.com Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Sat, 07 Jun 2014 00:21:27 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /ubuntu/dists/trusty/InRelease HTTP/1.1 Host: archive.ubuntu.com Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Sat, 07 Jun 2014 00:08:34 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /appgrid/stable/ubuntu/dists/trusty/InRelease HTTP/1.1 Host: ppa.launchpad.net Cache-Control: max-age=0 Accept: text/* Range: bytes=213- If-Range: Thu, 05 Jun 2014 14:53:42 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) GET /torproject.org/dists/trusty/InRelease HTTP/1.1 Host: deb.torproject.org Cache-Control: max-age=0 Accept: text/* If-Modified-Since: Fri, 30 May 2014 11:28:02 GMT User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) HTTP/1.1 200 OK Content-Type: text/html; charset=UTF-8 Content-Length: 213 Date: Sat, 07 Jun 2014 00:21:32 GMT Server: Apache/2.2.22 (Ubuntu) Vary: Accept-Encoding Get:1 http://archive.ubuntu.com trusty InRelease [213 B] 94% [1 InRelease 213 B/213 B 100%] [Waiting for headers] [Waiting for headers] GET /ubuntu/dists/trusty-updates/InRelease HTTP/1.1 Host: archive.ubuntu.com Cache-Control: max-age=0 Accept: text/* User-Agent: Debian APT-HTTP/1.3 (1.0.1ubuntu2) HTTP/1.1 200 OK Content-Type: text/html; charset=UTF-8 Content-Length: 213 Date: Sat, 07 Jun 2014 00:21:32 GMT Server: Apache/2.2.22 (Ubuntu) Vary: Accept-Encoding Get:2 http://extras.ubuntu.com trusty InRelease [213 B] 97% [1 InRelease gpgv 213 B] [Connecting to archive.ubuntu.com (91.189.92.200)]Splitting up /var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_trusty_InIgn http://archive.ubuntu.com trusty InRelease E: GPG error: http://archive.ubuntu.com trusty InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?) 当我运行sudo apt-get update时，我得到了错误：
Ign http://br.archive.ubuntu.com trusty InRelease E: GPG error: http://br.archive.ubuntu.com trusty InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)
要解决这个问题，首先我尝试：
wget https://dl.dropbox.com/u/8850924/fixpackage chmod +x ./fixpackage sudo ./fixpackage
建议在https://answers.launchpad.net/ubuntu/+question/251767
但它对我不起作用。 所以最后我尝试了以下几行，它解决了我的问题：
sudo apt-get clean sudo mv /var/lib/apt/lists /var/lib/apt/lists.broke sudo mkdir -p /var/lib/apt/lists/partial sudo apt-get update
我有同样的错误，但通过防火墙启用从/到（系统）的互联网流量解决了问题。