最近，我更新了我的所有宝石，并收到了这条消息：
~/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/rubygems/ext/builder.rb:73: warning: Insecure world writable dir /usr/local in PATH, mode 040777
这是什么意思？
我正在学习Ruby，并在运行我的Rails应用程序后收到了这个：
$ gem update
或：
$ rails server
我跑了：
$ brew doctor
并收到此消息：
Warning: Some directories in /usr/local/share/man aren't writable.
This can happen if you "sudo make install" software that isn't managed
by Homebrew. If a brew tries to add locale information to one of these
directories, then the install will fail during the link step.
You should probably `chown` them:
/usr/local/share/man/de
/usr/local/share/man/de/man1
Warning: Unbrewed .pc files were found in /usr/local/lib/pkgconfig.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.
Unexpected .pc files:
/usr/local/lib/pkgconfig/jack.pc
Warning: Some directories in your path end in a slash.
Directories in your path should not end in a slash. This can break other
doctor checks. The following directories should be edited:
~/.nvm/v0.10.28/lib/node_modules/coffee-script/bin/
Warning: Some keg-only formula are linked into the Cellar.
Linking a keg-only formula, such as gettext, into the cellar with
`brew link <formula>` will cause other formulae to detect them during
the `./configure` step. This may cause problems when compiling those
other formulae.
Binaries provided by keg-only formulae may override system binaries
with other strange results.
You may wish to `brew unlink` these brews:
freetype
但由于某些原因，我不知道，如果我这样做，我会遇到TeXShop的问题（我做了这个，当我跑$ brew link freetype时它恢复正常。）
所以我跑了：
$ brew update
$ brew doctor
并且问题仍然存在。
安装的插孔为jackosx