Either-or dependencies

dragonchild has asked for the wisdom of the Perl Monks concerning the following question:

I've received a request for DBM::Deep to allow for pure-perl versions of various modules, such as Digest::MD5 and Digest::MD5::Perl. The solution when loading is to eval the use and fail appropriately. However, I'm not quite sure how to do the dependencies for Module::Build (or ExtUtils::MakeMaker). Essentially, I want to go through the following steps:

Do you have Digest::MD5 installed?
If not, do you have Digest::MD5::Perl installed?
If not, ask which one you want to have installed.

Is this a feature of MB or EUMM? If not, what would the simplest way of putting this into my Build.PL (or Makefile.PL - I'm willing to switch back) be?

My criteria for good software:

Does it work?
Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

Comment on Either-or dependencies

Replies are listed 'Best First'.
Re: Either-or dependencies by adrianh (Chancellor) on Oct 01, 2007 at 13:37 UTC
Is this a feature of MB or EUMM Take a look at features() and auto_features() in M::B. No idea of the status of support for these in CPANPLUS.	[reply]
Re^2: Either-or dependencies by dragonchild (Archbishop) on Oct 01, 2007 at 15:05 UTC
I can't find that in either the POD or source of MB. What are you referring to? My criteria for good software: Does it work? Can someone else come in, make a change, and be reasonably certain no bugs were introduced?	[reply]
Re^3: Either-or dependencies by Limbic~Region (Chancellor) on Oct 01, 2007 at 19:07 UTC
dragonchild, Doing a CPAN Search for auto_features turned up Module::Build::API. From the description "I list here some of the most important methods in Module::Build." Cheers - L~R	[reply]