Wine 2.0rc6 no longer prompts to install gecko & mono

[symmetry]

This post refers to the development branch of Wine; specifically 2.0rc6, though it likely applies to other very recent versions in the development branch as well.

In the past, I was always prompted to install gecko or mono when running a program in a new Wine prefix. However, this stopped happening lately, and it may have caused problems with programs that need gecko. At least one other person has also reported this problem: viewtopic.php?f=8&t=27257

As far as I know, the development branch doesn't use wine-gecko or wine-mono even when they are installed from the operating system's repositories. Therefore, the only way to install Gecko when Wine doesn't prompt the user is to download it manually from here: https://wiki.winehq.org/Gecko

But the instructions there don't work either. That page tells users to download the .msi file, put it in /usr/share/wine/gecko, and then run the program that requires Gecko. I was skeptical this would work, considering I don't even have the wine directory under /usr/share, but I did it anyways and Gecko was not used afaik.

So this brings up 2 questions:
1. Why isn't Wine prompting me to install gecko and mono anymore? Was this an intended feature change?
2. How can I install gecko and mono manually when the instructions at https://wiki.winehq.org/Gecko don't work properly?

[dimesio]

Wine doesn't prompt you for gecko or mono if you have the .msi files on your system in a place Wine can find it; it just installs it to the wineprefix. And it caches the downloaded .msi files in ~/.cache/wine, so it will not prompt you after the first time.

So, are you really sure gecko and mono aren't getting installed in new wineprefixes? What does wine uninstaller show?