gn had the same problem when I looked at it in 2017. I was working with breakpad at the time (a Chromium subproject), and unfortunately they had only partially

gn had the same problem when I looked at it in 2017. I was working with breakpad at the time (a Chromium subproject), and unfortunately they had only partially ported some platforms to gn, and I didn't feel like plumbing in 3 different build systems for the 3 different platforms. Long story short, gn was painful without the internal documentation Googlers presumably had.