Ability to use non-private libavl?

[rmustacc]

When building in an environment such as the SmartOS platform, it'd be nice to not need to embed a copy of libavl and allow use of an external one. I'd be happy to code up something that'd work and allow us to pass something like USE_SYSTEM_LIBAVL=1 in the environment, if that'd be acceptable.

[davepacheco]

I'm not sure this is worthwhile. It's conceivable (even if not likely) that libavl would evolve and mdb_v8 would wind up tied to a newer version. In that case, newer mdb_v8 versions wouldn't be buildable in the context of older platforms. Maybe that's never desirable (because older platforms would have locked down the version of mdb_v8 that they're building), and it's arguably an issue with the build for those older platforms anyway.

The other reason is that this expands the test matrix -- builds would need to be regularly tested in both configurations.

Is the purpose just to avoid the extra disk space and memory used for the private copy?