• use buildroot_pkgs substitution type according to job.chroot
• use timeout command to respect timeout param coming from frontend
• don't ship unitfiles in %%bindir
• move createrepo to the end of the rawhide_to_release handler
• modulemd 1.0.2 compatibility
• Bug 1397119 - Error reading SSH protocol banner
• added auto-prune project's option
• Bug 1086139 - [RFE] provide UI to cancel a build
• Fix misleading debug statement
• fix exception logging in ensure_dir_exists helper
• Fix chroot_setup_cmd regex for custom chroot

• fix NameError: global name 'result' is not defined
• fix exception logging
• Modularity support
• Bug 1357564 - RFE: allow downloading of mock profiles (reproducible builds)
• "safer" exception handling for actions
• also provide default version and release for generated modules.json

• wrap feedback about actions to frontend into try-except
• log even the traceback from forking
• use makedirs instead of mkpath in fork action
• if anything bad happens, log exception in generate_gpg_key action
• also restart copr-backend-vmm and copr-backend-log when (re)installing
• Bug 1361344 - RFE: Allow denial of build deletion and resubmitting at project or group level
• catch errors in fork action
• set action result for comps.xml and module_md.yaml file deletion
• backend fork action now takes care of new gpg-key generation instead of frontend
• removed no longer supported --api-version=0.8 arg from appstream-builder command line
• specify module_md as module type
• fix saving comps.xml and module_md.yaml into empty copr (with no build)
• module_md.yaml is added to repodata now similarly to appstream.xml
• support for generation of module dist tags
• module_md.yaml uploading for a chroot
• simplified build and action task workflow
• use copy of the mock (chroot) config, not the original in /etc/mock/

Only minor changes compared to copr-backend-1.89.