For this type of error, after an OSX migration: Use of uninitialized value $version in substr at /loader/0x855460/App/perlbrew.pm line 19. …

The reason is the missing execution bit on a perlbrew perl installation ex: ~/perl5/perlbrew/perls/perl-5.14.2/bin/perl)

From: http://apple.stackexchange.com/a/58701 (Scott Pack)

For various and sundry reasons upgrading the OS requires one to separately upgrade/reinstall MacPorts. The developers have actually created a pretty nice Migration page that details the process necessary to get your ports environment working again after upgrading the OS.

Summarized, the steps you need to follow are:

1. Download and install new Xcode.
2. Make sure command line (gcc, make, etc.) tools are installed. From within the Xcode application go to Preferences→Downloads and install them.
3. Download the MacPorts installer of choice for your OS version.
4. Install it.
5. Open your terminal of choice.
6. Run the command

   port -qv installed > myports.txt

   This grabs a copy of all installed ports.

7. Uninstall all the ports:

   sudo port -f uninstall installed

8. Tidy up your play area:

   sudo port clean all

9. Go through the file myports.txt and reinstall the packages you actually want.

I actually sped up my reinstall process by editing the myports.txt file, such that it contained the names (and only the names) of the packages I wanted with one package per line, and running the following command

cat myports.txt | xargs -n1 port install

What this does is go through that file and execute the command port install line for every line in the file. It is a useless use of cat, butwho cares, it's easier to read.

From http://www.perlbrew.pl Then curl -kL http://install.perlbrew.pl | bash