Heroku CLI installation error: "PATH not updated, original length 1585 > 1024"
I may be too late to answer this question but I'll share what worked for me, in case some one else ran into the same issue. Basically, with time my path variable had too many variables added to it, and apparently, there is a characters limit that can be added to the PATH variable. I deleted a few variables in the PATH that I do not need anymore, and that was all!
I got it to work on Windows 10.
I tried two things and I'm unsure which one got Heroku to work. The first thing you can try is adding it to PATH in CMD or Git Bash in this post.
You should also try to manually add it to PATH by going to Settings->Advanced System Settings->Environment Variables and adding a system variable with name PATH and with value "C:\Program Files\Heroku\bin" or wherever you have your heroku.exe file.
This will manually update the PATH.