在製作鬧鐘時，由於會需要用到Realm這個第三方套件，所以今天就來了解一下。

一開始是因為要學習Realm的用法，發現Realm要先用Cocoapods安裝，糟糕的是安裝Cocoapods時的時候跳出了下面這個東西

Building native extensions. This could take a while...
ERROR:  Error installing cocoapods:
ERROR: Failed to build gem native extension.

在網路上搜尋一下之後，發現問題可能是出在ruby的版本太舊，於是輸入

% ruby -v

解果顯示版本確實太舊，需要更新一下

ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin20]

更新ruby

為了更新ruby，輸入

% brew install ruby

然後就是一陣等待和一堆下載之後，跳出下面這些東西

You may want to add this to your PATH.

ruby is keg-only, which means it was not symlinked into /usr/local,
because macOS already provides this software and installing another version in
parallel can cause all kinds of trouble.

If you need to have ruby first in your PATH, run:
echo 'export PATH="/usr/local/opt/ruby/bin:$PATH"' >> ~/.zshrc

For compilers to find ruby you may need to set:
export LDFLAGS="-L/usr/local/opt/ruby/lib"
export CPPFLAGS="-I/usr/local/opt/ruby/include"
  

大致看來應該是類似說明，於是按照說明設置PATH

% echo 'export PATH="/usr/local/opt/ruby/bin:$PATH"' >> ~/.zshrc 
% export LDFLAGS="-L/usr/local/opt/ruby/lib" >> ~/.zshrc       
% export CPPFLAGS="-I/usr/local/opt/ruby/include" >> ~/.zshrc

然後輸入

% source ~/.zshrc

就能看到已安裝的ruby，再來就是確保ruby

% ruby -v              
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-darwin20]
% which ruby
/usr/local/opt/ruby/bin/ruby

安裝Cocoapods

再次嘗試安裝Cocoapods了，輸入

% sudo gem install -n /usr/local/bin cocoapods

最後跳出下面這些就表示安裝成功了，可以開始使用啦

Done installing documentation for nanaimo, colored2, claide, CFPropertyList, atomos, xcodeproj, ruby-macho, nap, molinillo, gh_inspector, fourflusher, escape, cocoapods-try, netrc, cocoapods-trunk, cocoapods-search, cocoapods-plugins, cocoapods-downloader, cocoapods-deintegrate, ffi, ethon, typhoeus, public_suffix, fuzzy_match, concurrent-ruby, httpclient, algoliasearch, addressable, zeitwerk, tzinfo, i18n, activesupport, cocoapods-core, cocoapods after 47 seconds    

補充

也可以直接輸入下面這串安裝Cocoapods

% brew install cocoapods

到這裡就能開始使用Cocoapods裡的東西了，明天就能初次嘗試使用Realm了。