On a fresh macOS installation there are three empty directories for add-ons available to all users:
/Library/Ruby /Library/Python /Library/Perl
Starting with OS X Lion (10.7), you need
sudo to install to these like
sudo gem install,
sudo easy_install or
sudo cpan -i.
An option to avoid sudo is to use an access control list:
chmod +a 'user:YOUR_NAME_HERE allow add_subdirectory,add_file,delete_child,directory_inherit' /Library/Python/3.6/site-packages,
for example, will let you add packages to Python 3.6 as yourself. That
is probably safer than changing the group ownership of the directory.
One reason is executables go in
/usr/local/bin. Usually this isn’t a
writable location. But if you installed Homebrew as we recommend,
/usr/local will be writable without sudo. So now you are good to
install the development tools you need without risking the use of sudo.
Rather than changing the rights on
/Library/Python, we recommend the
easy_install is deprecated. We install
Python 2) along with python/python2.
We set up distutils such that
pip install will always put modules in
$(brew --prefix)/lib/pythonX.Y/site-packages and scripts in
$(brew --prefix)/share/python. Therefore, you won’t need sudo!
brew info python or
brew info python@2 for precise information
about the paths. Note, a brewed Python still searches for modules in
/Library/Python/X.Y/site-packages and also in
This is only recommended if you don’t use a brewed Python.
On macOS, any Python version X.Y also searches in
That dir might not yet exist, but you can create it:
mkdir -p ~/Library/Python/2.7/lib/python/site-packages
pip to install there, either use the
--user switch or create a
~/.pydistutils.cfg file with the
[install] install_lib = ~/Library/Python/$py_version_short/lib/python/site-packages
creates isolated Python environments with separate site-packages,
therefore you won’t need sudo.
If you use rbenv or RVM then you should ignore this stuff
Brewed Ruby installs executables to
without sudo. You should add this to your path. See the caveats in the
ruby formula for up-to-date information.
To make Ruby install to
/usr/local, we need to add
gem: -n/usr/local/bin to your
~/.gemrc. It’s YAML, so do it manually
or use this:
echo "gem: -n/usr/local/bin" >> ~/.gemrc
However, all versions of RubyGems before 1.3.6 are buggy and ignore the above setting. Sadly a fresh install of Snow Leopard comes with 1.3.5. Currently the only known way to get around this is to upgrade rubygems as root:
sudo gem update --system
Just install everything into the Homebrew prefix like this:
echo "export GEM_HOME=\"$(brew --prefix)\"" >> ~/.bashrc
Note, maybe you shouldn’t do this on Lion, since Apple has decided it is not a good default.
If you ever did a
sudo gem, etc. before then a lot of files will have
been created owned by root. Fix with:
sudo chown -R $USER /Library/Ruby /Library/Perl /Library/Python
The Perl module
local::lib works similarly to rbenv/RVM (although for
modules only, not perl installations). A simple solution that only
/Library/Perl a little is to install
local::lib with sudo:
sudo cpan local::lib
Note that this will install some other dependencies like
Then put the appropriate incantation in your shell’s startup, e.g. for
.bash_profile you insert the below, for others see the
eval $(perl -I$HOME/perl5/lib/perl5 -Mlocal::lib)
Now (after you restart your shell)
perl -MCPAN -eshell etc.
will install modules and binaries in
~/perl5 and the relevant
subdirectories will be in your
If you don’t even want (or can’t) use sudo for bootstrapping
local::lib, just manually install
~/perl5 and add the relevant path to
PERL5LIB before the .bashrc eval incantation.
Another alternative is to use
perlbrew to install a separate copy of Perl in your home directory, or wherever you like:
curl -L https://install.perlbrew.pl | bash perlbrew install perl-5.16.2 echo ".~/perl5/perlbrew/etc/bashrc" >> ~/.bashrc