A Fix for Perl SSL on MacOS X 10.11

UPDATE (August 12, 2017) – Check out Tom Vander Aa’s comment in the comments. His solution is better than my solution in the original post – it has much less chance of breaking other stuff that uses OpenSSL.

ORIGINAL:

When trying to install some Perl Programming Language modules on MacOS X, using a perlbrew-built perl, I was getting some weird linking errors with various OpenSSL headers.  Here’s an example from Net::SSLeay:

laptop$ cpan install Net::SSLeay
...
Configuring M/MI/MIKEM/Net-SSLeay-1.72.tar.gz with Makefile.PL
CPAN::Reporter not installed.  No reports will be sent.
*** Found OpenSSL-0.9.8z installed in /usr
*** Be sure to use the same compiler and options to compile your OpenSSL, perl,
    and Net::SSLeay. Mixing and matching compilers is not supported.
...
cc -c   -fno-common -DPERL_DARWIN -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -O3   -DVERSION=\"1.72\" -DXS_VERSION=\"1.72\"  "-I/Users/jmaslak/perl5/perlbrew/perls/perl-5.22.1/lib/5.22.1/darwin-2level/CORE"   SSLeay.c
SSLeay.xs:163:10: fatal error: 'openssl/err.h' file not found
#include <openssl/err.h>
         ^
1 error generated.
make: *** [SSLeay.o] Error 1
  MIKEM/Net-SSLeay-1.72.tar.gz
  /usr/bin/make -- NOT OK

I highlighted the interesting parts – I run homebrew on my Mac to manage development tools and the like. Sure enough, it had installed openssl already:

laptop$ brew install openssl
Warning: openssl-1.0.2e already installed

Hmmm, version 1.0.2e, which doesn’t look like the 0.9.8z that Net::SSLeay found.

A bit of Googling and scratching my head and I found the magic incantation:

laptop$ brew link openssl --force

Once that was done, I could successfully install Net::SSLeay and other SSL Perl modules.  I’m guessing that the links broke sometime during an OS upgrade. Hopefully this post will save you a bit of time!