Ruby新版本如何升级不清楚

Question

请参阅下面我用来升级到最新版本 Ruby 的终端命令。它在某一时刻说“ruby 3.2.0 已经安装并且是最新的”，但是当我运行“ruby -v”时它仍然返回旧版本Ruby。我做错了什么吗？

➜  ~ ruby -v            
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
➜  ~ brew install ruby  
Error: 
homebrew-core is a shallow clone.
To `brew update`, first run:
git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
This command may take a few minutes to run due to the large size of the repository.
This restriction has been made on GitHub's request because updating shallow
clones is an extremely expensive operation due to the tree layout and traffic of
Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
automatically to avoid repeatedly performing an expensive unshallow operation in
CI systems (which should instead be fixed to not use shallow clones). Sorry for
the inconvenience!
Warning: ruby 3.2.0 is already installed and up-to-date.
To reinstall 3.2.0, run:
brew reinstall ruby
➜  ~ ruby -v
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
➜  ~ brew reinstall ruby
==> Fetching ruby
==> Downloading https://ghcr.io/v2/homebrew/core/ruby/manifests/3.2.0
Already downloaded:                    /Users/Madeline/Library/Caches/Homebrew/downloads/c360900acacef49e831b0f640b0e175180c181ef83afbcd24d4d6609fbf146fe--ruby-3.2.0.bottle_manifest.json
==> Downloading https://ghcr.io/v2/homebrew/core/ruby/blobs/sha256:c25553dfc94e9
Already downloaded:     /Users/Madeline/Library/Caches/Homebrew/downloads/f587974e09ec9fbb07b125260da3ce05b66e91a92ec27898f2e446b81a840b88--ruby--3.2.0.monterey.bottle.tar.gz
==> Reinstalling ruby 
==> Pouring ruby--3.2.0.monterey.bottle.tar.gz
==> Caveats
By default, binaries installed by gem will be placed into:
/usr/local/lib/ruby/gems/3.2.0/bin

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"

For pkg-config to find ruby you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/ruby/lib/pkgconfig"

==> Summary
🍺  /usr/local/Cellar/ruby/3.2.0: 16,574 files, 44.8MB
==> Running `brew cleanup ruby`...
Disable this behaviour by setting HOMEBREW_NO_INSTALL_CLEANUP.
Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).
➜  ~ ruby -v
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
➜  ~ 

我希望“ruby -v”在运行命令“brew reinstall ruby”后返回最新版本 (3.2.0)。 它仍在返回旧版本。

Answer 1

使用 Homebrew 安装 Ruby 时，brew 不会使安装的版本自动成为系统上的默认 Ruby 版本，因为这会覆盖您的操作系统可能正在使用的系统 Ruby。

安装后的消息中对此进行了解释：

==> Caveats
By default, binaries installed by gem will be placed into:
/usr/local/lib/ruby/gems/3.2.0/bin

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"

For pkg-config to find ruby you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/ruby/lib/pkgconfig"

也就是说：当您想使用新的 Ruby 版本时，您需要按照该消息中的步骤进行操作，并且需要按照所述设置或重新配置环境变量。 完成后，您需要重新启动终端（甚至机器）以使这些更改生效。

覆盖系统 Ruby，并且不能在 Ruby 的不同版本之间切换，通常被视为一种不好的做法。 因此，人们通常建议使用 Ruby 版本管理器，提供更灵活。 您可能需要查看 Ruby 版本管理器，如rbenv 、 RVM或Ruby asdf 版本管理器插件。