May I humbly suggest that this project adapt some sort of git structure, e.g. something similar to:
I just got started today with setting up for mangOH Red, but immediately got stuck with the issue in The mangOH repository now uses a Legato 18.05.1 feature
The Sierra Legato page (https://source.sierrawireless.com/resources/airprime/software/legato_application_development_kit_linux/) unfortunately sports a rather old release of Legato, which then downloads the latest master branch of mangOH, causing build breakage.
Unfortunately, the git log of the mangOH repository is very hard to get a grip on when there are no releases or other possible breakage points, so there’s no obvious point to fall back to. At least some tagging and a develop branch would be huge steps forward!