我以前在 vagrant 中安装了插件。现在在另一台 MacBook 上，我正在尝试安装一些我在旧 MacBook 上使用的相同插件。
例如，当我尝试安装 vagrant-hostmanager 时，出现 ruby 权限错误：
$ vagrant plugin install vagrant-hostmanager
Installing the 'vagrant-hostmanager' plugin. This can take a few minutes...
Bundler, the underlying system Vagrant uses to install plugins,
reported an error. The error is shown below. These errors are usually
caused by misconfigured plugin installations or transient network
issues. The error from Bundler is:
An error occurred while installing ffi (1.9.8), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.8'` succeeds before bundling.
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/opt/vagrant/embedded/bin/ruby extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/opt/vagrant/embedded/bin/ruby
--with-ffi_c-dir
--without-ffi_c-dir
--with-ffi_c-include
--without-ffi_c-include=${ffi_c-dir}/include
--with-ffi_c-lib
--without-ffi_c-lib=${ffi_c-dir}/
--with-libffi-config
--without-libffi-config
--with-pkg-config
--without-pkg-config
/opt/vagrant/embedded/lib/ruby/2.0.0/tmpdir.rb:92:in `mktmpdir': parent directory is world writable but not sticky (ArgumentError)
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:510:in `try_link0'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:534:in `try_link'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:427:in `have_devel?'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:433:in `try_do'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:549:in `block in try_compile'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:502:in `with_werror'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:549:in `try_compile'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:1044:in `block in have_header'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:895:in `block in checking_for'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:894:in `checking_for'
from /opt/vagrant/embedded/lib/ruby/2.0.0/mkmf.rb:1043:in `have_header'
from extconf.rb:16:in `<main>'
Gem files will remain installed in /Volumes/Passport/vagrant.d/gems/gems/ffi-1.9.8 for inspection.
Results logged to /Volumes/Passport/vagrant.d/gems/gems/ffi-1.9.8/ext/ffi_c/gem_make.out
不同的一件事是，由于我的本地 SSD 空间有限，我在 .bashrc 中定义了以下内容：
export VAGRANT_HOME=/Volumes/Passport/vagrant.d
所以我的盒子文件存储在 2TB USB3 驱动器上，而不是占用宝贵的 SSD 空间。
现在我可以使用 sudo 执行插件安装，但这成为一个级联问题，因为vagrant up现在无法在 Vagrantfile 中看到插件而不执行sudo vagrant up. 然后虚拟机归根用户所有……你可以看到这是如何级联失控的。
有谁知道出了什么问题？我怎么可能解决？
编辑：我发现如果我改VAGRANT_HOME回默认值~/.vagrant.d，我可以安装插件 - 但是我的盒子现在位于默认设置无法访问的卷上。显然这是 Ruby 的限制。
蒂亚！