[DX] Testing changes in x/net (net/http/h2_bundle.go issue) with gotip

[Kirth Gersen]

hi,

I'm struggling to build a program using changes made to golang.org/x/net.

Using "replace" in go.mod works fine for a change that doesn't require net/http to be updated.

But because of h2_bundle.go 'trick' in net/http the std lib must be updated for the changes to be integrated in net/http.

This video explains the h2_bundle.go trick: https://www.youtube.com/watch?v=FARQMJndUn0&t=814s

I've tried using gotip but it gets complicated because of "vendor" bits in std lib source.

I managed to get around this but I find the whole experience not very user friendly.

Then I get an error when trying to "go generate net/http":

bundle: internal error: package "strings" without types was imported from "golang.org/x/net/http2"
net/http/http.go:5: running "bundle": exit status 1

(is this related to generics introduction in 1.18 and not having them in golang.org/x/net yet ?)

Are there recommended/better steps to test changes made to golang.org/x/net ?

here the steps I used:

• # install latest dev go env
• gotip download
• # clone golang.org/x/net into GOPATH (could be any other directory)
• git clone https://go.googlesource.com/net $(gotip env GOPATH)/src/golang.org/x/net
• # do some changes in golang.org/x/net, for instance :
• cd $(gotip env GOPATH)/src/golang.org/x/net
• git fetch https://go.googlesource.com/net refs/changes/34/362834/10 && git checkout -b change-362834 FETCH_HEAD
• # modify gotip root env to point to modified golang.org/x/net
  
• cd $(gotip env GOROOT)/src
• echo "replace golang.org/x/net => $(gotip env GOPATH)/src/golang.org/x/net" >>go.mod
• gotip mod vendor   # ? otherwise we'll get an error
• # next step would be ./make.bash
• # but this doesn't "go generate" a new h2_bundle so we have do it manually first
• cd $(gotip env GOROOT)/src
• gotip generate net/http # this requires the bundle tool to be installed
• # error here

Another issue is that gotip doesn't have a 'make' option only 'download'. gotip doesn't generate either (could be on purpose).

so gotip is probably not the right tool to test changes made to golang.org/x/net ?

I've read https://go.dev/doc/contribute but it doesn't provide much information about using a modified go root env.

[Ian Lance Taylor]

On Mon, Dec 6, 2021 at 6:11 AM Kirth Gersen <kirth...@gmail.com> wrote:
>
> Then I get an error when trying to "go generate net/http":
>
> bundle: internal error: package "strings" without types was imported from "golang.org/x/net/http2"
> net/http/http.go:5: running "bundle": exit status 1
> (is this related to generics introduction in 1.18 and not having them in golang.org/x/net yet ?)

Make sure to run "gotip install golang.org/x/tools/cmd/bundle" with
gotip, so that bundle understands the export data used by gotip.

Ian

[Kirth Gersen]

> Make sure to run "gotip install golang.org/x/tools/cmd/bundle" with
> gotip, so that bundle understands the export data used by gotip.

thx that indeed fixed the error.