Both armv7 and aarch64 support gnat but gprbuild doesn't those architectures. There's been a few requests for the ADA stack on the ARM architectures so it would be nice if we could support the full stack on armv7 and aarch64
This bug appears to have been reported against 'rawhide' during the Fedora 23 development cycle. Changing version to '23'. (As we did not run this process for some time, it could affect also pre-Fedora 23 development cycle bugs. We are very sorry. It will help us with cleanup during Fedora 23 End Of Life. Thank you.) More information and reason for this action is here: https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora23
Fixed in #2015