x/pkgsite: modernc.org/* pages are showing 404

[julieqiu]

Reported in https://groups.google.com/forum/#!msg/golang-nuts/40Qkf-_kgWM/_JB613CNAAAJ:

godoc.org displays packages from the domain modernc.org just fine. It
also adds a banner sayings, for example at
https://godoc.org/modernc.org/cc/v3

    "Pkg.go.dev is a new destination for Go discovery & docs.

Check it out at pkg.go.dev/modernc.org/cc/v3 and share your
feedback."

However, clicking that link (ie. https://pkg.go.dev/modernc.org/cc/v3)
is a 404. In fact, all modernc.org packages I have tried just minutes
ago, about 20 of them, are 404.

The feedback is: Please either fix pkg.go.dev or do not put the banner
in godoc that does not work and may confuse package users. FTR, it
seems all the modernc.org packages are still present in the pkg.do.dev
search index and I remember that the packages used to be shown there.
I have not asked anyone to remove them, so I suppose some glitch must
have happened somewhere.

I have tried to follow the instructions found here:
https://go.dev/about#adding-a-package but I see no change. However,
it's not clear if there's some delay involved between triggering the
process and the results being available. I suggest adding that
particular piece of information to the instructions.

I'd appreciate a reply from anyone having insight into this. Thanks in advance.

[gopherbot]

Change https://golang.org/cl/241061 mentions this issue: internal/frontend: fix parsing of /mod prefix

[gopherbot]

Change https://golang.org/cl/241063 mentions this issue: internal/frontend: fix mod prefix