最近在学习深度学习，首先学习的是torch框架。安装torch可以根据官网，看起来很简单，但是确实会遇到各种困难。

1.Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/ftp.sjtu.edu.cn_ubuntu_dists_precise-security_restricted_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

这是运行第二步遇到的问题，然后网上提供了一种方法：

sudo rm /var/lib/apt/lists/* -vf
sudo apt-get update

2.ar: strmm_kernel_LN.o: No such file or directorymake[1]: *** [libs] Error 1make[1]: Leaving directory `/tmp/OpenBLAS/kernel'make: *** [libs] Error 1Error. OpenBLAS could not be compiled

在网上找到了一个解决办法

sudo apt-get install vim  #安装过vim的忽略此命令
vim ~/torch/install-deps

这时你会看见（15-19行）：

if [ $(getconf _NPROCESSORS_CONF) == 1 ]; then
    make NO_AFFINITY=1 USE_OPENMP=0 USE_THREAD=0
else
    make NO_AFFINITY=1 USE_OPENMP=1
fi

键入i进入插入模式，在make语句后面添加BINARY=32，修改后结果如下：

if [ $(getconf _NPROCESSORS_CONF) == 1 ]; then
    make NO_AFFINITY=1 USE_OPENMP=0 USE_THREAD=0 BINARY=32
else
    make NO_AFFINITY=1 USE_OPENMP=1 BINARY=32
fi

修改完成后，按下ESC，键入:wq保存退出，重新执行bash instal-deps即可完成安装：

···
Generating OpenBLASConfig.cmake in /opt/OpenBLAS/lib/cmake/openblas
Generating OpenBLASConfigVersion.cmake in /opt/OpenBLAS/lib/cmake/openblas
Install OK!
make[1]: Leaving directory `/tmp/OpenBLAS'
==> Torch7's dependencies have been installed

make[2]: *** [lib/TH/CMakeFiles/TH.dir/THVector.c.o] Error 1make[1]: *** [lib/TH/CMakeFiles/TH.dir/all] Error 2make: *** [all] Error 2Error: Build error: Failed building.

在网上也可以找到相关的解决办法

gcc版本是gcc-4.8，需要升级至gcc-5：

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-5 g++-5
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5

gcc升级后，重新执行./install.sh即可完成安装：

···
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