x/pkgsite: slow to download std when running locally

[adonovan]

Steps to reproduce:

• $ go run golang.org/x/pkgsite/cmd/pkgsite@master &
• $ open http://localhost:8080
• Enter "fmt", hit Return, see search results page.
• Click first link for package fmt
• Wait 17s for download of std@latest.
• See documentation for fmt.

Ideally we would eliminate step 5. Is it necessary to select std@latest when there's a recent version of std already already installed?

Perhaps std@installedversion could also be offered on the "Or browse local modules:" menu, since just as it is desirable for the docs to reflect the local edits to modules, so too it is desirable to show the version of Go that is installed locally.

Loosely related:

• x/pkgsite: large module pages are very slow to render #51564
• x/pkgsite: slower loads than godoc.org #38892

[seankhliao]

There's the -gorepo flag for use with a checkout of the go repo
Though i still don't know how to get pkgsite to show "contents of my current CL" for std

related #57742

[adonovan]

There's the -gorepo flag for use with a checkout of the go repo

Thanks. I tried it twice, once with -gorepo=$(dirname $(dirname $(go list -f {{.Dir}} fmt))) to be consistent with the installed go command on the $PATH, and once with -goroot=$HOME/w/goroot which is a git client. In neither case did it reduce the latency of loading std. I haven't dug in to investigate.