The json file loads, but then all I get after that is a CRC error.
I have the zip on my web hosting server and have verified the size and hash more than a few times on Windows and Linux so I think there is something else wrong, also tried with a nightly build of IDE from last night.
json is at:
https://github.com/epccs/epccs-board-index/
board setup (very likely to have bugs) [edit: third try]
https://github.com/epccs/epccs-avr/
got past CRC problem now it is saying
processing.app.debug.TargetPlatformException: Could not find boards.txt in C:\Users\rsutherland\AppData\Roaming\Arduino15\packages\epccs.org\hardware\avr\0.0.0. Is it pre-1.5?
I don't understand what is going on with the 0.0.0. at the end, my json file has that as the version but why is it expected after avr\
Also tags on github seem to differ in how they can be downloaded, it only allows me to download an archive with the tag appended, but I see others have access without the tag.
Well it is working now, so time to start debugging the other problems.
I had the folder layout almost right with my first try, but could not get past the CRC checking, after figuring that out with my second setup I had put things under an avr folder, so the IDE could not find my boards.txt file.
It looks like the version needs found at the end of the file name of the top level in the zip archive.
I also see that a file can be uploaded for use with a release, this seems to be how access without tags is done. It is probably a way to provide a binary of the release.