doc: document that now that js is a GOOS that can break existing packages

[VojtechVitek]

I found a build regression when building a large monorepo when trying out Go 1.11-beta1.

Please check out this repo: github.com/VojtechVitek/go1.11, the simplest reproducer I came up with.

Go 1.10.3

$ go version
go version go1.10.3 darwin/amd64

$ go run main.go
OK

Go 1.11-beta1

$ go version
go version go1.11beta1 darwin/amd64

$ go run main.go
# command-line-arguments
./main.go:11:6: undefined: addons.CustomJS

Looks like Go 1.11-beta1 ignores the addons/custom_js.go file for some reason.

Is _js.go suffix somehow magical now because of the js/wasm support?

Is this intended? I don't think I saw this in the Go 1.11 DRAFT release notes.

Thanks!

System details

go version go1.11beta1 darwin/amd64
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/vojtechvitek/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/vojtechvitek/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/hr/5zb8r0yx4sv4_1dc0rlccflm0000gn/T/go-build846962860=/tmp/go-build -gno-record-gcc-switches -fno-common"
VGOMODROOT=""
GOROOT/bin/go version: go version go1.11beta1 darwin/amd64
GOROOT/bin/go tool compile -V: compile version go1.11beta1
uname -v: Darwin Kernel Version 17.4.0: Sun Dec 17 09:19:54 PST 2017; root:xnu-4570.41.2~1/RELEASE_X86_64
ProductName:	Mac OS X
ProductVersion:	10.13.3
BuildVersion:	17D47
lldb --version: lldb-902.0.79.2
  Swift-4.1

[ianlancetaylor]

This is an unfortunate consequence of adding js as a recognized GOOS value. It means that files named "xxx_js.go" will now only be built when building for WASM. We've run into this problem before. I don't know of a good solution. Clearly it needs to be documented.

[ianlancetaylor]

CC @andybons

[davecheney]

js is now an operating system, like windows, as far as go build is concerned https://github.com/golang/go/blob/master/src/go/build/syslist.go#L7 So any file ending with _js will be ignored unless you've set GOOS=js

…

On 12 July 2018 at 00:02, Vojtech Vitek ***@***.***> wrote: I found a build regression when building a large monorepo when trying out Go 1.11-beta1. Please check out this repo: github.com/VojtechVitek/go1.11, the simplest reproducer I came up with. Go 1.10.3 $ go version go version go1.10.3 darwin/amd64 $ go run main.go OK Go 1.11-beta1 $ go version go version go1.11beta1 darwin/amd64 $ go run main.go # command-line-arguments ./main.go:11:6: undefined: addons.CustomJS Looks like Go 1.11-beta1 ignores the addons/custom_js.go <https://github.com/VojtechVitek/go1.11/blob/master/addons/custom_js.go> file for some reason. Is _js.go suffix somehow magical now because of the js/wasm support? Is this intended? I don't think I saw this in the Go 1.11 DRAFT release notes <https://tip.golang.org/doc/go1.11>. Thanks! System details go version go1.11beta1 darwin/amd64 GOARCH="amd64" GOBIN="" GOCACHE="/Users/vojtechvitek/Library/Caches/go-build" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/vojtechvitek/go" GOPROXY="" GORACE="" GOROOT="/usr/local/go" GOTMPDIR="" GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64" GCCGO="gccgo" CC="clang" CXX="clang++" CGO_ENABLED="1" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/hr/5zb8r0yx4sv4_1dc0rlccflm0000gn/T/go-build846962860=/tmp/go-build -gno-record-gcc-switches -fno-common" VGOMODROOT="" GOROOT/bin/go version: go version go1.11beta1 darwin/amd64 GOROOT/bin/go tool compile -V: compile version go1.11beta1 uname -v: Darwin Kernel Version 17.4.0: Sun Dec 17 09:19:54 PST 2017; root:xnu-4570.41.2~1/RELEASE_X86_64 ProductName: Mac OS X ProductVersion: 10.13.3 BuildVersion: 17D47 lldb --version: lldb-902.0.79.2 Swift-4.1 — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#26329>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcA7GUsB4xFF8jyKsb3xtJJHl11X7Gks5uFgVogaJpZM4VLMv4> .

[VojtechVitek]

Documenting for others, since the issue was renamed:

Issue: Go 1.11 ignores *_js.go files when building the source code

(unless you explicitly build for GOOS=js WASM target)

Fix: Rename *_js.go files to *_javascript.go or similar

[andybons]

@neelance

[gopherbot]

Change https://golang.org/cl/123416 mentions this issue: doc: mention that *_js.go files are now ignored and treated like a GOOS