最近因为pod search 无法查询到最新第三方库，需要更有cocoapods。记录过程遇到的问题。
1. 首先安装 pod执行sudo gem installcocoapods。
报错
ERROR:Error installing cocoapods:
activesupport requires Ruby version >= 2.2.2.
提示Ruby版本过低，需要升级Ruby
2.升级Ruby
2.1 查看Ruby版本
ruby -v
ruby 2.0.0p648 (2015-12-16 revision 53162) [universal.x86_64-darwin15] 确实版本过低。
2.2 升级Ruby 需要安装rvm
如果已经安装可以忽略。
没有安装需要执行以下命令
curl -L get.rvm.io | bash -s stable
source ~/.bashrc
source ~/.bash_profile
检测是否安装成功 rvm -v
输出 rvm 1.29.3 (master) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io].即可
2.3 查看可以安装ruby版本 rvm list known
输出
# MRI Rubies[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10][ruby-]2.2[.8]
[ruby-]2.3[.5]
[ruby-]2.4[.2]
[ruby-]2.5[.0-preview1]ruby-head# for forks use: rvm install ruby-head---url https://github.com/github/ruby.git --branch 2.2
# JRuby
jruby-1.6[.8]
jruby-1.7[.27]
jruby[-9.1.13.0]
jruby-head
# Rubinius
rbx-1[.4.3]
rbx-2.3[.0]
rbx-2.4[.1]
rbx-2[.5.8]
rbx-3[.86]
rbx-head
# Opal
opal
# Minimalistic ruby implementation - ISO 30170:2012
mruby-1.0.0
mruby-1.1.0
mruby-1.2.0
mruby-1[.3.0]
mruby[-head]
# Ruby Enterprise Edition
ree-1.8.6
ree[-1.8.7][-2012.02]
# Topaz
topaz
# MagLev
maglev[-head]
maglev-1.0.0
# Mac OS X Snow Leopard Or Newer
macruby-0.10
macruby-0.11
macruby[-0.12]
macruby-nightly
macruby-head
# IronRuby
ironruby[-1.1.3]
ironruby-head
2.4 安装最新的是rvm install ruby-head---url
报错404 可能和网络相关无奈只好尝试其他版本。
rvm install 2.4.2
报错
'Failed to update Homebrew, follow instructions here
XXXX
Requirements installation failed with status: 1.
提示 需要升级brew。
3.升级brew
执行 brew update
报错基本是一些权限问题，修改文件权限即可。
执行成功查看版本brew --version
Homebrew 1.3.5
Homebrew/homebrew-core (git revision a75a9; last commit 2017-10-16)
4.重新安装Ruby
rvm install 2.4.2
4.1报错：error: RPC failed; curl 56 SSLRead() return error -36
一般原因是因为装了多个Xcode造成的
卸载，安装最新xcode即可或者执行
sudo xcode-select-switch/Applications/Xcode.app/Contents/Developer也可。
再次执行rvm install 2.4.2
4.2报错：Library not loaded: /usr/local/opt/openssl@1.1/lib/libssl.1.1.dylib (LoadError)
卸载 ruby rvm uninstall 2.4.2
重新安装 rvm reinstall 2.4.2 （很重要）。
4.3再次报错
*** Following extensions failed to configure:
../.././ext/gdbm/extconf.rb:0: Failed to configure gdbm. It will not be installed.
*** Fix the problems, then remove these directories and try again if you want.
make[2]: `ruby' is up to date.
making enc
make[1]: Nothing to be done for `enc'.
making trans
make[1]: Nothing to be done for `./enc/trans'.
making encs
make[1]: Nothing to be done for `encs'.
./miniruby -I./lib -I. -I.ext/common ./tool/runruby.rb --extout=.ext -- --disable-gems -r./x86_64-darwin16-fake ./tool/rbinstall.rb --make="/Applications/Xcode.app/Contents/Developer/usr/bin/make" --dest-dir="" --extout=".ext" --mflags="" --make-flags="" --data-mode=0644 --prog-mode=0755 --installed-list .installed.list --mantype="doc"
installing binary commands: /Users/jeff/.rvm/rubies/ruby-2.4.2/bin
dyld: lazy symbol binding failed: Symbol not found: _utimensat
Referenced from: /Users/jeff/.rvm/src/ruby-2.4.2/libruby.2.4.2.dylib
Expected in: /usr/lib/libSystem.B.dylib
dyld: Symbol not found: _utimensat
Referenced from: /Users/jeff/.rvm/src/ruby-2.4.2/libruby.2.4.2.dylib
Expected in: /usr/lib/libSystem.B.dylib
make: *** [do-install-nodoc] Abort trap: 6
++ return 2
卸载重新安装试了多次无效。最后尝试是XCode不是最新原因
可以安装最新Xcode如果还是不行，可以执行以下命令
brew install rbenv ruby-build
sudo xcode-select --install
4.4 重新安装 rvm reinstall 2.4.2 终于成功。
查看版本 ruby -v
ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-darwin16]
5 最后安装pod即可 执行
sudo gem install cocoapods
5.1 gem source -r https://ruby.taobao.org/ （淘宝资源不能用）
增加新的资源地址
gem source -a https://gems.ruby-china.org/
pod setup 等待即可
