If I'm not mistaken: when the 15.0-ALPHA1 installer uses base packages
from FreeBSD Project-provided repos, the result is inferior
15.0-PRERELEASE, for which there is (still) a
`FreeBSD-kernel-generic-nodebug` package, and so on.
Seeking 15 at <https://pkg-status.freebsd.org/builds?type=package> finds
no jail name that begins with 15.
Do we need additional builders, for alphas, betas, and release candidates?
Maybe already work in progress; Colin's hope of "soon" at
<https://www.reddit.com/r/freebsd/comments/1naxy9v/comment/nd1dfui/>
with regard to pkgbase packages shipping on the install images.
----
Thanks to /u/pavetheway91 at
<https://www.reddit.com/r/freebsd/comments/1naxy9v/comment/nd4z750/> for
a related catch. (Someone else might have expressed things in a
different way. The penny didn't drop, for me, until this morning.)