I am not sure if this is a question for this list or for the APR forum, but it seems to me that this forum is more likely to have an answer.
To what extent can I expect a module compiled on system A to be portable to system B: -- if both are running the same distribution of linux, though possibly not the same release -- if system A and system B are both running Apache 2.4.x, though possibly not the same release -- if system A has a custom-built Apache and system B has a distribution release of Apache I'm asking because several people don't want to compile their own modules (can't imagine why, it's so easy an Einstein can do it) and asked for ready-to-go kits that they can drop in and go. APR seems to me to be a black box, and if one of my modules calls a reslib that may not be present in another machine or at a different level, it seems to me there's potential problems there; and yet APR being a black box, it is going to be difficult to force static linking against libraries instead of resident libraries if APR intends to go that way.