I get this -

GOOS=js GOARCH=wasm ./make.bash
cmd/go: unsupported GOOS/GOARCH pair js/wasm

What am I missing ?

@agnivade, that's the complete output? I don't see how that's possible. There are echo statements in make.bash before it ever runs go.

Figured it out. It is this line which runs before the echo statements - https://github.com/golang/go/blob/master/src/make.bash#L144.

goroot=$(GOROOT='' "$go_exe" env GOROOT)

I am using Go1.10 to bootstrap. Hence it does not support js/wasm pair. Should I use the tip binary itself to bootstrap ?

Also, how do I run tests ? I see this -

22:58:34-agniva-~/play/gosource/go/src$GOOS=js GOARCH=wasm ../bin/go test encoding/hex
fork/exec /tmp/go-build165629863/b001/hex.test: exec format error
FAIL	encoding/hex	0.001s

Obviously wasm won't run natively. Do I need to use go_js_wasm_exec somewhere ?

I'm bootstrapping with Go 1.4, but make.bash works for me. What is your complete output of make.bash when it fails and what is your environment?

Yes, you need go_js_wasm_exec in your $PATH, and you need nodejs installed to run the "node" binary.

What is your complete output of make.bash when it fails and what is your environment?

That is it :)

23:45:20-agniva-~/play/gosource/go/src$GOOS=js GOARCH=wasm ./make.bash
cmd/go: unsupported GOOS/GOARCH pair js/wasm

linux/amd64. Ubuntu 16.04.

Just guessing, but probably 1.4 does not have an explicit whitelist of GOOS/GOARCH pairs like 1.10 ?

Yes, you need go_js_wasm_exec in your $PATH, and you need nodejs installed to run the "node" binary.

Ah gotcha.

You didn't answer the question about what is in your environment. Do you define GOROOT_BOOTSTRAP?

Just guessing, but probably 1.4 does not have an explicit whitelist of GOOS/GOARCH pairs like 1.10 ?

Might be related, but I can build js/wasm with go1.10:

$ GOROOT_BOOTSTRAP=$HOME/go1.10 GOOS=js GOARCH=wasm ./make.bash 
Building Go cmd/dist using /home/bradfitz/go1.10.
Building Go toolchain1 using /home/bradfitz/go1.10.
Building Go bootstrap cmd/go (go_bootstrap) using Go toolchain1.
Building Go toolchain2 using go_bootstrap and Go toolchain1.
...

Ah, by environment, you meant environment variables. No I am not defining GOROOT_BOOTSTRAP. And by explicitly defining it, it works because it bypasses that check on L144 :)

01:10:37-agniva-~/play/gosource/go/src$GOROOT_BOOTSTRAP=/usr/local/go GOOS=js GOARCH=wasm ./make.bash
Building Go cmd/dist using /usr/local/go.
Building Go toolchain1 using /usr/local/go.
Building Go bootstrap cmd/go (go_bootstrap) using Go toolchain1.
Building Go toolchain2 using go_bootstrap and Go toolchain1.
Building Go toolchain3 using go_bootstrap and Go toolchain2.
Building packages and commands for host, linux/amd64.
Building packages and commands for target, js/wasm.
---
Installed Go for js/wasm in /home/agniva/play/gosource/go
Installed commands in /home/agniva/play/gosource/go/bin

Thank you for helping me debug this.

@agnivade, want to resume work on this now?

Yea I had. But faced minor bumps while persevering through the code.

I can see that the tooldir variable holds the location for the tools getting built. And where the tools like link, compile and asm are getting built. But I can't figure out where is the other stuff like gofmt, api are getting built. Any pointers to those will be very helpful.

Change https://golang.org/cl/120655 mentions this issue: cmd/dist: skip building tools for js/wasm