This commit addresses this. So this issue can be closed. Thanks a lot!
The build version is 5.x-68e8507efb72. According to the OpenFOAM news there was a patch release end of October 2017. I guess this is the version where the API changed. If I remember correctly the new OpenFOAM development rule is to maintain backwards compatibility for the major versions. For me this includes not changing the API but apparently it did. I can only imagine the amount of effort you put into swak4foam to make it work with all these OpenFOAM versions and forks out there. However it is...
Compile error for unitCylinderSearchableSurface
Comment 16ff of a post at CFD-Online contains a possible solution to this issue.
Post comment 16ff at CFD_Online contains a possible solution to this issue.
conky fails to build with ncurses if ncurses itself is built with the terminfo option