Installing Term::ReadLine::Gnu on OS X, the easy way
If you try to install Term::ReadLine::Gnu on Mac OS X, you will ordinarily run into this unpleasantry from the
Makefile.PL (which will likely end up in such as
The libreadline you are using is the libedit library. Use the GNU Readline Library.
Here I will assume that you are using Homebrew and have installed GNU Readline:
brew install readline
Even so, you will get this error. This is because of how Homebrew installs Readline. Since OS X ships libedit as libreadline, Homebrew tries to avoid conflicts with system software by installing Readline as “keg-only” software – that is, it’ll install it within its package-managed filesystem hierarchy beneath
/usr/local/Cellar, but it won’t link the libraries into
/usr/local/lib, so that they won’t be visible to software that isn’t explicitly linked against it.
There is an easy and obvious way around this:
brew link --force readline cpanm Term::ReadLine::Gnu brew unlink readline
This makes Homebrew link the shared libraries into
/usr/local/lib – which Homebrew ordinarily refuses to do for packages marked keg-only, like Readline is, hence the scary
--force. Of course, all said and done, we unlink the package again straight away, so as to not cause conflicts. By doing this,
Makefile.PL run from cpanm picks them up to link. We can confirm this:
otool -L ~/perl5/perlbrew/perls/**/Term/ReadLine/Gnu/Gnu.bundle
Its output should include something like the following line:
/usr/local/opt/readline/lib/libreadline.6.2.dylib (compatibility version 6.0.0, current version 6.2.0)
/usr/local/opt is another Homebrew-ism:
$ ls -l /usr/local/opt/readline lrwxr-xr-x 1 user admin 24 14 Jul 04:53 /usr/local/opt/readline@ -> ../Cellar/readline/6.2.4
Note well that I actually have Readline 6.2.4 installed!
$ brew info readline | head -1 readline: stable 6.2.4