Vscode extension builds failing: "Exit code: 3221225781"

3221225781 is 0xC0000135 which is STATUS_DLL_NOT_FOUND.

I’ve had the most success diagnosing DLL problems with procmon, running it in background then uploading the trace to my server for analysis. See Failing to run compiled Python extension for details.

Other that that, can’t say anything with the information given.

You are also probably doing yourself a disservice suppressing output with --silent, it might contain useful hints. For starters, it’s not even clear what exactly exits with that code.