I've finally been clued into why git-annex isn't working on Android 5, and it seems fixing it is as easy as pie.. That is, passing -pie -FPIE to the linker. I've added a 5.0 build to the Android autobuilder. It is currently untested, so I hope to get feedback from someone with an Android 5 device; a test build is now available.
I've been working through the backlog of messages today, and gotten down from 170 to 128. Mostly answered a lot of interesting questions, such as "Where to start reading the source code?"
Also did some work to make git-annex check git versions at runtime more often, instead of assuming the git version it was built against. It turns out this could be done pretty inexpensively in 2 of 4 cases, and one of the 2 fixed was the git check-attr behavior change, which could lead to git-annex add hanging if used with an old version of git.