我有一个反复出现的问题， 有时build立基本不可用，而试图安装AWS上的Ubuntu 12.04.2（使用ubuntu提供的ami：ami-ce7b6fba）。
创build实例的脚本：
set -o xtrace set -e sudo apt-get update sudo apt-get -y install build-essential 相当恼人的是它有时可以工作。 我试图添加eu-west-1 Ubuntu镜像，但是这并没有解决问题。
有任何想法吗？
输出：
amazon-ebs: ++ set -e amazon-ebs: ++ sudo apt-get update amazon-ebs: Get:1 http://security.ubuntu.com precise-security Release.gpg [198 B] amazon-ebs: Hit http://archive.ubuntu.com precise Release.gpg amazon-ebs: Get:2 http://security.ubuntu.com precise-security Release [49.6 kB] amazon-ebs: Get:3 http://archive.ubuntu.com precise-updates Release.gpg [198 B] amazon-ebs: Hit http://archive.ubuntu.com precise Release amazon-ebs: Get:4 http://archive.ubuntu.com precise-updates Release [49.6 kB] amazon-ebs: Hit http://archive.ubuntu.com precise/main amd64 Packages amazon-ebs: Get:5 http://security.ubuntu.com precise-security/main amd64 Packages [309 kB] amazon-ebs: Hit http://archive.ubuntu.com precise/restricted amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/universe amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/main i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/restricted i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/universe i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/main TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/restricted TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/universe TranslationIndex amazon-ebs: Get:6 http://security.ubuntu.com precise-security/restricted amd64 Packages [4627 B] amazon-ebs: Get:7 http://archive.ubuntu.com precise-updates/main amd64 Packages [677 kB] amazon-ebs: Get:8 http://security.ubuntu.com precise-security/universe amd64 Packages [80.9 kB] amazon-ebs: Get:9 http://security.ubuntu.com precise-security/multiverse amd64 Packages [2442 B] amazon-ebs: Get:10 http://security.ubuntu.com precise-security/main i386 Packages [325 kB] amazon-ebs: Get:11 http://security.ubuntu.com precise-security/restricted i386 Packages [4620 B] amazon-ebs: Get:12 http://security.ubuntu.com precise-security/universe i386 Packages [84.1 kB] amazon-ebs: Get:13 http://archive.ubuntu.com precise-updates/restricted amd64 Packages [11.5 kB] amazon-ebs: Get:14 http://security.ubuntu.com precise-security/multiverse i386 Packages [2633 B] amazon-ebs: Get:15 http://archive.ubuntu.com precise-updates/universe amd64 Packages [211 kB] amazon-ebs: Get:16 http://security.ubuntu.com precise-security/main TranslationIndex [74 B] amazon-ebs: Get:17 http://security.ubuntu.com precise-security/multiverse TranslationIndex [72 B] amazon-ebs: Get:18 http://archive.ubuntu.com precise-updates/multiverse amd64 Packages [13.8 kB] amazon-ebs: Get:19 http://security.ubuntu.com precise-security/restricted TranslationIndex [72 B] amazon-ebs: Get:20 http://archive.ubuntu.com precise-updates/main i386 Packages [698 kB] amazon-ebs: Get:21 http://security.ubuntu.com precise-security/universe TranslationIndex [73 B] amazon-ebs: Get:22 http://security.ubuntu.com precise-security/main Translation-en [149 kB] amazon-ebs: Get:23 http://archive.ubuntu.com precise-updates/restricted i386 Packages [11.4 kB] amazon-ebs: Get:24 http://archive.ubuntu.com precise-updates/universe i386 Packages [215 kB] amazon-ebs: Get:25 http://security.ubuntu.com precise-security/multiverse Translation-en [1299 B] amazon-ebs: Get:26 http://archive.ubuntu.com precise-updates/multiverse i386 Packages [14.0 kB] amazon-ebs: Hit http://security.ubuntu.com precise-security/restricted Translation-en amazon-ebs: Get:27 http://archive.ubuntu.com precise-updates/main TranslationIndex [3564 B] amazon-ebs: Get:28 http://security.ubuntu.com precise-security/universe Translation-en [51.8 kB] amazon-ebs: Get:29 http://archive.ubuntu.com precise-updates/multiverse TranslationIndex [2605 B] amazon-ebs: Get:30 http://archive.ubuntu.com precise-updates/restricted TranslationIndex [2461 B] amazon-ebs: Get:31 http://archive.ubuntu.com precise-updates/universe TranslationIndex [2850 B] amazon-ebs: Get:32 http://archive.ubuntu.com precise/main Translation-en [726 kB] amazon-ebs: Get:33 http://archive.ubuntu.com precise/multiverse Translation-en [93.4 kB] amazon-ebs: Get:34 http://archive.ubuntu.com precise/restricted Translation-en [2395 B] amazon-ebs: Get:35 http://archive.ubuntu.com precise/universe Translation-en [3341 kB] amazon-ebs: Get:36 http://archive.ubuntu.com precise-updates/main Translation-en [306 kB] amazon-ebs: Get:37 http://archive.ubuntu.com precise-updates/multiverse Translation-en [8064 B] amazon-ebs: Get:38 http://archive.ubuntu.com precise-updates/restricted Translation-en [2637 B] amazon-ebs: Get:39 http://archive.ubuntu.com precise-updates/universe Translation-en [125 kB] amazon-ebs: Fetched 7582 kB in 8s (930 kB/s) amazon-ebs: Reading package lists... Done amazon-ebs: ++ sudo apt-get -y install build-essential amazon-ebs: Reading package lists... Done amazon-ebs: Building dependency tree amazon-ebs: Reading state information... Done amazon-ebs: Package build-essential is not available, but is referred to by another package. amazon-ebs: This may mean that the package is missing, has been obsoleted, or amazon-ebs: is only available from another source amazon-ebs: amazon-ebs: E: Package 'build-essential' has no installation candidate
当它工作时：
amazon-ebs: ++ set -e amazon-ebs: ++ sudo apt-get update amazon-ebs: Get:1 http://security.ubuntu.com precise-security Release.gpg [198 B] amazon-ebs: Hit http://archive.ubuntu.com precise Release.gpg amazon-ebs: Get:2 http://security.ubuntu.com precise-security Release [49.6 kB] amazon-ebs: Get:3 http://archive.ubuntu.com precise-updates Release.gpg [198 B] amazon-ebs: Hit http://archive.ubuntu.com precise Release amazon-ebs: Get:4 http://archive.ubuntu.com precise-updates Release [49.6 kB] amazon-ebs: Hit http://archive.ubuntu.com precise/main amd64 Packages amazon-ebs: Get:5 http://security.ubuntu.com precise-security/main amd64 Packages [309 kB] amazon-ebs: Hit http://archive.ubuntu.com precise/restricted amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/universe amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse amd64 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/main i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/restricted i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/universe i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse i386 Packages amazon-ebs: Hit http://archive.ubuntu.com precise/main TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/restricted TranslationIndex amazon-ebs: Hit http://archive.ubuntu.com precise/universe TranslationIndex amazon-ebs: Get:6 http://archive.ubuntu.com precise-updates/main amd64 Packages [677 kB] amazon-ebs: Get:7 http://archive.ubuntu.com precise-updates/restricted amd64 Packages [11.5 kB] amazon-ebs: Get:8 http://archive.ubuntu.com precise-updates/universe amd64 Packages [211 kB] amazon-ebs: Get:9 http://archive.ubuntu.com precise-updates/multiverse amd64 Packages [13.8 kB] amazon-ebs: Get:10 http://archive.ubuntu.com precise-updates/main i386 Packages [698 kB] amazon-ebs: Get:11 http://security.ubuntu.com precise-security/restricted amd64 Packages [4627 B] amazon-ebs: Get:12 http://security.ubuntu.com precise-security/universe amd64 Packages [80.9 kB] amazon-ebs: Get:13 http://security.ubuntu.com precise-security/multiverse amd64 Packages [2442 B] amazon-ebs: Get:14 http://security.ubuntu.com precise-security/main i386 Packages [325 kB] amazon-ebs: Get:15 http://archive.ubuntu.com precise-updates/restricted i386 Packages [11.4 kB] amazon-ebs: Get:16 http://archive.ubuntu.com precise-updates/universe i386 Packages [215 kB] amazon-ebs: Get:17 http://security.ubuntu.com precise-security/restricted i386 Packages [4620 B] amazon-ebs: Get:18 http://security.ubuntu.com precise-security/universe i386 Packages [84.1 kB] amazon-ebs: Get:19 http://archive.ubuntu.com precise-updates/multiverse i386 Packages [14.0 kB] amazon-ebs: Get:20 http://security.ubuntu.com precise-security/multiverse i386 Packages [2633 B] amazon-ebs: Get:21 http://security.ubuntu.com precise-security/main TranslationIndex [74 B] amazon-ebs: Get:22 http://security.ubuntu.com precise-security/multiverse TranslationIndex [72 B] amazon-ebs: Get:23 http://archive.ubuntu.com precise-updates/main TranslationIndex [3564 B] amazon-ebs: Get:24 http://security.ubuntu.com precise-security/restricted TranslationIndex [72 B] amazon-ebs: Get:25 http://archive.ubuntu.com precise-updates/multiverse TranslationIndex [2605 B] amazon-ebs: Get:26 http://security.ubuntu.com precise-security/universe TranslationIndex [73 B] amazon-ebs: Get:27 http://archive.ubuntu.com precise-updates/restricted TranslationIndex [2461 B] amazon-ebs: Get:28 http://security.ubuntu.com precise-security/main Translation-en [149 kB] amazon-ebs: Get:29 http://archive.ubuntu.com precise-updates/universe TranslationIndex [2850 B] amazon-ebs: Hit http://archive.ubuntu.com precise/main Translation-en amazon-ebs: Hit http://archive.ubuntu.com precise/multiverse Translation-en amazon-ebs: Hit http://archive.ubuntu.com precise/restricted Translation-en amazon-ebs: Get:30 http://security.ubuntu.com precise-security/multiverse Translation-en [1299 B] amazon-ebs: Hit http://security.ubuntu.com precise-security/restricted Translation-en amazon-ebs: Hit http://archive.ubuntu.com precise/universe Translation-en amazon-ebs: Get:31 http://security.ubuntu.com precise-security/universe Translation-en [51.8 kB] amazon-ebs: Get:32 http://archive.ubuntu.com precise-updates/main Translation-en [306 kB] amazon-ebs: Get:33 http://archive.ubuntu.com precise-updates/multiverse Translation-en [8064 B] amazon-ebs: Get:34 http://archive.ubuntu.com precise-updates/restricted Translation-en [2637 B] amazon-ebs: Get:35 http://archive.ubuntu.com precise-updates/universe Translation-en [125 kB] amazon-ebs: Fetched 3420 kB in 2s (1637 kB/s) amazon-ebs: Reading package lists... Done amazon-ebs: ++ sudo apt-get -y install build-essential amazon-ebs: Reading package lists... Done amazon-ebs: Building dependency tree amazon-ebs: Reading state information... Done amazon-ebs: The following extra packages will be installed: amazon-ebs: binutils cpp cpp-4.6 dpkg-dev amazon-ebs: fakeroot g++ g++-4.6 gcc gcc-4.6 amazon-ebs: libalgorithm-diff-perl amazon-ebs: libalgorithm-diff-xs-perl amazon-ebs: libalgorithm-merge-perl libc-bin amazon-ebs: libc-dev-bin libc6 libc6-dev amazon-ebs: libdpkg-perl libgomp1 libmpc2 amazon-ebs: libmpfr4 libquadmath0 amazon-ebs: libstdc++6-4.6-dev linux-libc-dev amazon-ebs: make manpages-dev amazon-ebs: Suggested packages: amazon-ebs: binutils-doc cpp-doc gcc-4.6-locales amazon-ebs: debian-keyring g++-multilib amazon-ebs: g++-4.6-multilib gcc-4.6-doc amazon-ebs: libstdc++6-4.6-dbg gcc-multilib amazon-ebs: autoconf automake1.9 libtool flex amazon-ebs: bison gdb gcc-doc gcc-4.6-multilib amazon-ebs: libmudflap0-4.6-dev libgcc1-dbg amazon-ebs: libgomp1-dbg libquadmath0-dbg amazon-ebs: libmudflap0-dbg binutils-gold amazon-ebs: glibc-doc libstdc++6-4.6-doc amazon-ebs: make-doc amazon-ebs: The following NEW packages will be installed: amazon-ebs: binutils build-essential cpp cpp-4.6 amazon-ebs: dpkg-dev fakeroot g++ g++-4.6 gcc amazon-ebs: gcc-4.6 libalgorithm-diff-perl amazon-ebs: libalgorithm-diff-xs-perl amazon-ebs: libalgorithm-merge-perl libc-dev-bin amazon-ebs: libc6-dev libdpkg-perl libgomp1 amazon-ebs: libmpc2 libmpfr4 libquadmath0 amazon-ebs: libstdc++6-4.6-dev linux-libc-dev amazon-ebs: make manpages-dev amazon-ebs: The following packages will be upgraded: amazon-ebs: libc-bin libc6 amazon-ebs: 2 upgraded, 24 newly installed, 0 to remove and 76 not upgraded
当它不起作用时， sudo wc -l /var/lib/dpkg/available返回：
9280 /var/lib/dpkg/available
啊，算出来。
apt-get dist-upgrade apt-get update apt-get install build-essential
修复了这个问题。