How to use that mscompile.cmd if I can only use the Microsoft Visual Studio 2015, if this one I had to use the regressions builds

[Rogus]

***PCSX2 version:***PCSX2 Libretro v0.1-alpha

PCSX2 options:
(For example, Clamping/Rounding, Speedhacks, GameFixes)
None, yet.

Plugins used:

None

Description of the issue:
(What's the problem? - Screenshots showing the issue if applicable)

How to reproduce the issue:
(Detailed step by step guide on how to replicate the issue)

Just using and executing the mscompile.cmd on the advanced versions of Windows 10 like 2004 and above
Last known version to work:
(If the issue isn't present in an older PCSX2 version, it would be helpful to mention the full title of that version. Narrowing it down to the build/commit that first introduced the issue is even better!)
None. Since I can't build. The only one I am trying to compile is this one
PCSX2 Libretro v0.1-alpha

PC specifications:
(For example: CPU: Intel Core 2 Duo E4600 GPU: Gigabyte GTX 750Ti OS: Windows 10 64 Bit)
CPU: AMD Athlon 200GE with Radeon Vega 3 Graphics | 4 Threads | 2 cores OS: Windows 10 64 bit version 2004| 13.93 GiB RAM out of 16 Gib in the motherboard ASRock A320M-HD

[psychonic]

I believe that the sln in the repo is from the upstream pcsx2. Instead, the cmake files are updated to support the libretro build.

This worked for me. You do need cmake installed. The third line generates project files that you can use in VS, and then you can build with VS or directly with the fourth line.

mkdir build-libretro
cd build-libretro
cmake .. -DLIBRETRO=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build . -- -p:Configuration=RelWithDebInfo