BUG #18459: running pg_ctl.exe from inside a program running as a Windows service returns "error code 6"

The following bug has been logged on the website:

Bug reference: 18459
Logged by: Rick Frank
Email address: rfrank(at)riministreet(dot)com
PostgreSQL version: 15.3
Operating system: Windows
Description:

We have a program written in Go that launches postgressql. Postgres starts
as a separate process, but under control of our program. This works fine
running the program interactively with our program in a folder under
“C:\Program Files”. But Postgres won’t start when we run our program as a
Windows service, even if the postgres programs and database are in a
different folder. If we have our program in any folder except “C:\Program
Files”, it works running as a service.

I tried with the service running under "Local System" and with a named
Administrator account; same error each time. I made sure that all users have
Full Control permissions to the folder where Postgres resides. Postgres
programs and data are in the same folder, in "C:\ProgramData" folder.

The program is using a Go package called embedded-postgres. That package
starts Postgres using pg_ctl.exe. Here is the error that pg_ctl.exe
returns:
"pg_ctl: could not start server: error code 6"

I can’t find any info saying what this message means. Any ideas what this
means?