Well…almost got OpenCV building on my main Ubuntu machine at home. I was copying fragments from the directions on the OpenCV site into an SSH session and clearly missed something along the way. I’ll have to build a single, large shell script up front next time and then run that. Unfortunately it seems as if (I may learn better later on) once CMake has done its magic, lots of things get baked into the files that drive the build in ways that really, really want a rebuild if things don’t go quite right.

I was working from the instructions here. (Other instructions here).

I was surprised to see that the github repo and contrib did not have a branch tag for release 4. It looks as if there’s a stable release out there, but 3.4 and master seemed like the available choices.

The main site clearly indicates that version 4 has been released with pre-built windows and ios downloads and documentation. I’m not sure currently how to pull that stable release code from git though.

I expect to take another run at the 4.0 build on Ubuntu tonight. Other than script grabbing issues, the build went smoothly…32 GB of memory and a Core-i5 CPU work better than an low-end ARM and 1 GB swapping on a micro-SD card.

Hmm…more github presence for version 4 here and here. Looks like OpenCV 4.0.1 is the latest. Ah…tags not branches here…need to look at pulling the appropriate tag for the build. Easy enough…just list the tags, find the 4.0.1 tag and check that out.