[build2] error when trying to compile build2

[Boris Kolpackov]

Phillip Shelton via users <users at build2.org> writes:

> curl -f -L -A "bpkg/0.14.0 (MinGW; +https://build2.org) libbpkg/0.14.0 libbutl/0.14.0 curl" https://pkg.cppget.org/1/alpha/repositories.manifest
>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
>                                  Dload  Upload   Total   Spent    Left  Speed
>   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
> curl: (60) SSL certificate problem: self signed certificate in certificate chain

Hm, strange. We have numerous Windows CI jobs doing exactly this
without any issues. Must be something special about your setup or
environment. Some possibilities that come to mind:

1. You are not using curl from the build2-baseutils package. You can
   try:

   > where curl
   > curl -Ov https://pkg.cppget.org/1/alpha/repositories.manifest

2. Something is man-in-the-middle'ing your connection and presenting
   a bogus certificate. Perhaps your organization requires you to
   connect via a proxy or some such?