build: Add script to fetch and build BDB 4.8 in-tree?

[laanwj]

Lots of people get stumped by the BDB 4.8 dependency. It is starting to be really hard to get in modern distros. Even if we were to go to some magic append-only wallet format we'll have to support it for foreseeable time for backwards compatibility.

I think a script that fetches BDB 4.8, configures and builds it statically would be useful.
Then change the bitcoin autoconf to automatically pick it up (and set include/library path accordingly) if it was fetched this way.

Note: I am not proposing to add BDB to the git repository like we did with leveldb. Just to make building against the "holy version" easier.

[Belkaar]

Why not include the source and directly build it into the binary?
db 4.8 needs to stay in for the foreseeable future anyways to import old wallets.

[laanwj]

There is already too much 'alien' code in here (leveldb, spirit-json), I want to reduce the amount of code in 'core' not increase it.

BDB is only used for the wallet and the wallet is planned to be split off to a seperate repository (see #3882). After that, at some point, including the BDB code may be acceptable. But I also doubt it (also depends on license issues and such).

This is an intermediate solution, which would be acceptable to even the most conservative devs and could be easy to implement and it is effectively the same as including it if done right.