You can also grab the hash via PowerShell and send that to VirusTotal as well if you don't feel like uploading the entire file, assuming it has been sent to VirusTotal before. From the hash, I think you're using the Beta 19 release.
You can additionally scan it via Windows Defender with the second command, Start-MpScan. You need to use the full path to the file because for some reason it doesn't like relative pathing with this command. If you do -ScanType Quick or Full, it will take quite a bit longer as it will scan startup items and other locations, but that works too.
Get-MpThreat should return a history of detected threats, if any have been found.
Historically, the only things that ever flag on Obsidian are scanners of unknown reputation and quality, or Windows Defender noting that it is not a common download (this especially happens when the release hasn't been up for very long).
I've updated COMPILING.md on the repo with instructions on compilation if you feel more comfortable doing it yourself. Beta 19 won't work with MSVC, but that is changing when 20 is released.