Glad that worked, can you post the contents of the cpanm log file for the failure, it's too hard to say what's wrong otherwise.

cpanm (App::cpanminus) 1.7043 on perl 5.018002 built for darwin-thread
+-multi-2level
Work directory is /Users/my_name/.cpanm/work/1501257286.35074
You have make /usr/bin/make
You have LWP 6.05
You have /usr/bin/tar: bsdtar 2.8.3 - libarchive 2.8.3
You have /usr/bin/unzip
Searching ExtUtils::PkgConfig () on cpanmetadb ...
--> Working on ExtUtils::PkgConfig
Fetching http://www.cpan.org/authors/id/X/XA/XAOC/ExtUtils-PkgConfig-1
+.16.tar.gz
-> OK
Unpacking ExtUtils-PkgConfig-1.16.tar.gz
Entering ExtUtils-PkgConfig-1.16
Checking configure dependencies from META.json
Checking if you have ExtUtils::MakeMaker 6.58 ... Yes (7.30)
Configuring ExtUtils-PkgConfig-1.16
Running Makefile.PL
***
*** ExtUtils::PkgConfig requires the pkg-config utility, but it doesn'
+t
*** seem to be in your PATH.  Is it correctly installed?
***  PATH=/Users/my_name/perl5/bin:/usr/local/bin:/usr/bin:/bin:/usr/s
+bin:/sbin:/Library/TeX/texbin
***
-> N/A
-> FAIL Configure failed for ExtUtils-PkgConfig-1.16. See /Users/my_na
+me/.cpanm/work/1501257286.35074/build.log for details.
[download]

The reason for failure is clear:

ExtUtils::PkgConfig requires the pkg-config utility, but it doesn't se
+em to be in your PATH.  Is it correctly installed?
[download]

ExtUtils::PkgConfig is an interface to a program called pkg-config, which doesn't seem to be available on your system, or isn't in anywhere in your PATH environment variable. Either add the installed location to your PATH variable, or install the software if you don't already have it. See brew.sh, then from the command line:

brew install pkg-config
[download]