[Arch / Manjaro / Mabox Linux] [ YAY ] Failed to download PKGBUILD. fatal: not a git repository

[ GIT_DISCOVERY_ACROSS_FILESYSTEM not set ] 

Dear anjaro's and rch'os users

I really spent almost all day figuring out why my yay Pacman wrapper was raising exit code 128, as shown below.
For this example, I used rustresk, but it does not matter which package I used - the side effect was the same. You can see the example below.

user@localhost# yay -S rustdesk

Sync Make Dependency (6): yasm-1.3.0-7, rust-1:1.86.0-1, cmake-4.0.2-1, ninja-1.12.1-2, python-toml-0.10.2-12, nasm-2.16.03-2
Sync Dependency (1): gst-plugin-pipewire-1:1.4.2-1
AUR Explicit (1): rustdesk-1.4.0-1
:: (0/1) Failed to download PKGBUILD: rustdesk
 -> error fetching rustdesk: fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set). 
	 context: exit status 128

I'm trying to find this issue by web search with Google search, but I found no proper results I found:

1. Add git init - this answer was so crazy, because an existing ~/.git directory without a repository and a branch is useless. But this semi-solution shows the next issue. Please read further
   

   user@localhost# git init

   
   
2. set GIT_DISCOVERY_ACROSS_FILESYSTEM - this is another semi-solution, which has not changed
   

   user@localhost# export GIT_DISCOVERY_ACROSS_FILESYSTEM=1
   
   or 
   
   user@localhost# GIT_DISCOVERY_ACROSS_FILESYSTEM=1 yay -S rustdesk
   

   but the output is changed for (options 1 and 2):

   user@localhost# yay -S rustdesk
    

   
   AUR Explicit (1): rustdesk-1.4.0-1
   Sync Make Dependency (6): yasm-1.3.0-7, python-toml-0.10.2-12, cmake-4.0.2-1, nasm-2.16.03-2, rust-1:1.86.0-1, ninja-1.12.1-2
   Sync Dependency (1): gst-plugin-pipewire-1:1.4.2-1
   :: (0/1) Failed to download PKGBUILD: rustdesk
    -> error fetching rustdesk: fatal: not a git repository (or any of the parent directories): .git 
   	 context: exit status 128
   

   
   

   Still, we are in  the same place... :(

3. In meantime, I do a lot of things yay -Syu, yay -Y --gendb, pacman -S rustdesk, pamac build rustdesk... and... last command install wanted app but... HOW is it possible?
   The answer is...

4. I saw that each tool uses a different scope (yay has its own directories, pamac has his own directories, pacman has its own package list with its own directory. The DIR is the key 

5. I found where yay is caching his PKGBUILD's zip files and... Viola! 
   I removed all wrong permitted directories from .cache/mmenu/yay/*
   

   user@localhost# sudo rm -Rf ~/.cache/mmenu/yay/*

Hurray!!! Enjoy the solution!

user@localhost# yay -S rustdesk 

AUR Explicit (1): rustdesk-1.4.0-1
Sync Dependency (1): gst-plugin-pipewire-1:1.4.2-1
Sync Make Dependency (6): python-toml-0.10.2-12, yasm-1.3.0-7, nasm-2.16.03-2, rust-1:1.86.0-1, cmake-4.0.2-1, ninja-1.12.1-2
:: PKGBUILD up to date, skipping download: rustdesk
  1 rustdesk                         (Build Files Exist)
==> Packages to cleanBuild?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)
==> none
  1 rustdesk                         (Build Files Exist)
==> PKGBUILDs to edit?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)