Currently this json file contains comments in C-style.
However, comments in json files are not allowed and they could
break external programs that make use of them.
To fix it, I removed any comment from org.gnome.Calendar.json file.
https://bugzilla.gnome.org/show_bug.cgi?id=781787
If using Builder 3.22.3, you can use this manifest to allow building
Calendar against the GNOME master SDK. This means that contributing to
Calendar can be as easy as installing Builder, cloning calendar, set the
manifest build preference,and Build/Run.
Carlo Lobrano