Hi YULdigitalpreservation, I've noticed that you added C++ as a programming language (P277) to a large number of projects around 30 January 2017. I've looked through some of the edits and noticed that they all have "stated in: English Wikipedia" reference. However, many of those projects don't mention C++ on their Wikipedia pages. What's more, they don't mention C++ on their official sites or sometimes even in their code statistics. I didn't look through all the projects, of course, and I also understand that C and C++ are pretty similar/interchangeable at times, but the nature of these mass-edits suggests that many of these claims are in error. Some examples:
git (Q186055): enwiki says "C, Shell, Perl, Tcl, Python", repo statistics say "C++ 1.6%" - a minimal amount for a projects with 12 years of history
Mercurial (Q476543): enwiki says "Python and C", openhub statistics say "C++ 0.3%"
Mirai (Q27517815): enwiki says "C (agent), Go (controller)", analysis page says "C&C (command and control) code is coded in Go, while its bots are coded in C", no mention of C++ anywhere
Flatpak (Q22661286): enwiki says "C", repo statistics don't mention C++ (maybe in "other 0.4%").
GTK+ (Q189464): enwiki says "C", repo statistics say "C++ 1.1%"
GNU Emacs (Q1252773): enwiki says "Emacs Lisp, C", repo statistics don't mention C++ (maybe in "other 2.6%")
libxslt (Q6542808): enwiki says "C", home page doesn't mention C++
Many more don't mention C++ on their wiki page, like libvpx (Q26259220), Fossil (Q1439431) but I couldn't find their language statistics.
Maybe the problem was in selecting appropriate projects for adding the claim? A broken regular expression that selects projects written in C (not C++)? I've never used Widar myself, but a software bug is always a possibility.