Thank you marto (+++),

That link, though outdated, really helped. I found a 4-year old tutorial for installing libdb4.8-dev and libdb4.8++-dev, so I searched apt-cache and found libdb5.3-dev and libdb5.3++-dev. After installing both of these building Perl's BerkeleyDB and MLDBM with cpanm both worked perfectly; no errors. My biased observation; my bad. I should have read the README :-( When all else fails, read the documentation. Without Monks to fall back on, I would be up the proverbial creek without a paddle. I have Geodesic great circle calculators written in C and Perl that use Berkeley DB I am very proud of and don't wish to lose. One uses spherical calculus, as in:

greatCircleBDB.pl* mapHashBDB 'Renton, WA' 'Redmond, OR'

Calculate great-circle distance between:
              Renton, WA: 0.828799, -2.132710 and,
             Redmond, OR: 0.772381, -2.114462.
  Geodesics in radians.
GCD (Spherical Law of Cosines) between Renton, WA and Redmond, OR: 368
+.430 km,
  (198.936 NM).
GCD (Haversine) between Renton, WA and Redmond, OR: 368.430 km,
  (198.936 NM).
GCD (Vincenty inverse formula) between Renton, WA and Redmond, OR: 368
+.336 km,
  (198.885 NM).
[download]

I can now continue exploring using Perl to solve advanced math problems, my hobby now that I'm retired (math minor from UofI, 1971. Crypto next up...

Thanks again.