log

Last 15 lines from /Users/<user>/Library/Logs/Homebrew/php56/01.configure:
checking for Apache 1.x module support... no
checking whether to enable Apache charset compatibility option... no
checking for Apache 2.0 filter-module support via DSO through APXS... no
checking for Apache 2.0 handler-module support via DSO through APXS... 

Sorry, I cannot run apxs.  Possible reasons follow:

1. Perl is not installed
2. apxs was not found. Try to pass the path using --with-apxs2=/path/to/apxs
3. Apache was not built using --enable-so (the apxs usage page is displayed)

The output of /usr/local/bin/apxs follows:
apxs:Error: /usr/local/Cellar/apr/1.5.2/libexec/bin/apr-1-config not found!.

configure: error: Aborting

READ THIS: https://git.io/brew-troubleshooting
If reporting this issue please do so at (not Homebrew/brew):
  https://github.com/Homebrew/homebrew-php/issues

These open issues may also help:
Updated php56-protobuf version. https://github.com/Homebrew/homebrew-php/pull/3272
brew install php56 https://github.com/Homebrew/homebrew-php/issues/2760
Make error php56 https://github.com/Homebrew/homebrew-php/issues/1842
PHP56 required for composer https://github.com/Homebrew/homebrew-php/issues/2796
failed to install php56-pthreads https://github.com/Homebrew/homebrew-php/issues/2768
Every update of php56 force me to reinstall php56-intl and php56-mcrypt with --build-from-source https://github.com/Homebrew/homebrew-php/issues/2440
Failed to install/reinstall php56-http https://github.com/Homebrew/homebrew-php/issues/2711
Can't install php56-mcrypt https://github.com/Homebrew/homebrew-php/issues/2452
Fails to Install Php56 with Imap Extensiton https://github.com/Homebrew/homebrew-php/issues/2703
I can't find php56_pdo! https://github.com/Homebrew/homebrew-php/issues/2706
Adds a new php70-gearman formula that updates php56-gearman https://github.com/Homebrew/homebrew-php/pull/3120
"brew upgrade" fails: php56 conflicting with php70 when upgrading phpmyadmin https://github.com/Homebrew/homebrew-php/issues/2945
Why does wp-cli formula try to install php56 if php70 is already there? https://github.com/Homebrew/homebrew-php/issues/3179
PHP56 can't launch as root, with nginx 500 Internal Server Error? https://github.com/Homebrew/homebrew-php/issues/2709

==> Upgrading homebrew/php/php56-intl
==> Installing dependencies for homebrew/php/php56-intl: php56
==> Upgrading homebrew/php/php56-mcrypt
==> Installing dependencies for homebrew/php/php56-mcrypt: php56