There is a difference between a distribution and the modules that it contains. If you look at the distribution Twiggy, you'll see it contains those modules, but if you look at the source of the modules, they don't define a $VERSION, which is allowed. Though personally I would try to give every module in a distribution the same version, when it comes to the installation, you don't need to worry about what version the individual modules of a distribution have - when defining dependencies, it's enough to define a dependency on the latest version of the module Twiggy to get all of the modules in its distribution installed.

Ok, I did take a gander through Twiggy, and realized that

requires 'Plack::Handler::Twiggy' => '0.1025';

was never gonna be satified. I altered the cpanfile to this:

#requires 'Plack::Handler::Twiggy' => '0.1025';
##      this module          ^^ is sliced up differently
requires 'AnyEvent::AIO' => '1.1';
requires 'Async::Interrupt' => '1.24';
requires 'Cookie::Baker::XS' => '0.09';
requires 'Device::Firmata' => '0.65';
requires 'Device::SerialPort' => '1.04';
requires 'Device::WebIO' => '0.022';
requires 'Device::WebIO::Dancer' => '0.004';
requires 'Device::WebIO::Firmata' => '0.002';
requires 'Device::WebIO::RaspberryPi' => '0.900';
requires 'DBD::SQLite' => '1.58';
requires 'DBI' => '1.641';
requires 'Guard' => '1.023';
requires 'GPS::NMEA' => '0.17';
requires 'Math::Round' => '0.07';
requires 'RPi::WiringPi' => '2.3628';
requires 'RPi::Pin' => '2.3606';
requires 'Plack::Handler::Twiggy' => 'undef';
requires 'Starman' => '0.4014';
requires 'Time::HiRes' => '1.9758';
requires 'Twiggy' => '0.1025';
requires 'WWW::Form::UrlEncoded::XS' => '0.25';
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, and got it the checks to pass:

$ cpanm --verbose --installdeps .
...
Checking if you have Plack::Handler::Twiggy 0 ... Yes (undef)
...
Checking if you have Twiggy 0.1025 ... Yes (0.1026)
...
$
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What's more, I looked ahead in stevieb's guide for source I might use, and I didn't see the module included in stuff that I was going to use anytime soon. I was super-pleased to have his guide to orient me through installing the camera:

The one downside of the CSI-2 connector is that it’s attached with a ribbon cable, which can be a bit flimsy. The connector sits by the HDMI port on most Pis. This shouldn’t be confused with the DSI (Display Serial Interface) connector, which sits near the SD card. ... Power off your Pi, and then insert the cable. You’ll see a small strip of tape along one edge of the ribbon cable. On most Pi’s, this will face the edge with the Ethernet and USB ports.

I was almost despondent when I saw that ribbon. Getting that in the right place the right way the first time was faith-promoting.

$ raspistill -o 1.test_pic.jpg

$ ls
 1.test_pic.jpg
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A clear and sharp photo results, flimsy ribbon notwithstanding....