Updating php56-apache2handler gives configure error

[Murray Eisenberg]

Just now with MacPorts 2.3.4 under El Capitan 10.11.1, trying to upgrade 

    php56-apache2handler 5.6.14_0 < 5.6.15_0

led to a configure error. The log shows:

:info:configure checking for Apache 2.0 handler-module support via DSO through APXS... 
:info:configure 
:info:configure Sorry, I cannot run apxs.  Possible reasons follow:
:info:configure 
:info:configure 1. Perl is not installed
:info:configure 2. apxs was not found. Try to pass the path using --with-apxs2=/path/to/apxs
:info:configure 3. Apache was not built using --enable-so (the apxs usage page is displayed)
:info:configure 
:info:configure The output of /opt/local/apache2/bin/apxs follows:
:info:configure ./configure: /opt/local/apache2/bin/apxs: /opt/local/bin/perl: bad interpreter: No such file or directory
:info:configure configure: error: Aborting

(1) Now Perl _is_ installed:

         sudo port installed | grep perl5
     :
     :
    perl5 @5.16.3_0+perl5_16
    perl5 @5.16.3_0+perl5_20
    perl5.12 @5.12.5_0
    perl5.16 @5.16.3_1 (active)
    perl5.18 @5.18.4_1 (active)
    perl5.20 @5.20.3_0 (active)
    perl5.22 @5.22.0_0 (active)

(2) And apxs is installed and ought to be found:

        which apxs
    /opt/local/apache2/bin/apxs
        echo $PATH
    /opt/local/bin: ... /opt/local/apache2/bin 

Which leaves possible reason (3), "Apache was not built using --enable-so (the apxs usage page is displayed)".

I find:

        httpd -l
    Compiled in modules:
     core.c
     prefork.c
     http_core.c
     mod_so.c

So what does "not built using --enable-so" mean and how should this be fixed?

Note that after migrating macports from Yosemite to El Capitan, I had no trouble installing the earlier version of php56-apache2handler.

---
Murray Eisenberg		murrayeisenberg at gmail.com
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