cmd/go: "go: stripping unprintable or unescapable characters from ..." for seemingly printable characters

[prattmic]

In #71857, the go env output shows several warnings like

go: stripping unprintable or unescapable characters from %"GOBIN"%
set GOBIN=C:\Users\������\Desktop\Go\bin

Later in the issue there is a screenshot of Powershell which seems capable of printing the characters just fine.

@chenjie199234 could you post the exact characters in your C:\Users\... path so we can see if there is an issue with the way cmd/go is handling these Unicode characters?

[seankhliao]

I wonder if this comes from Windows being in GB or Big5 (is that possible?)
cc @golang/windows

[dagood]

This seemed pretty straightforward to reproduce in both PowerShell (Core) and Windows PowerShell with OCR to grab a repro-ing string from the screenshot. Oddly (to me) it doesn't happen when telling go env to only print a specific variable:

$ $env:GOBIN='C:\test\陈杰\test'

$ go env
[...]
set GOAUTH=netrc
go: stripping unprintable or unescapable characters from %"GOBIN"%
set GOBIN=C:\test\������\test
set GOCACHE=C:\Users\dagood\AppData\Local\go-build
[...]
set GOVERSION=go1.24.0
set GOWORK=
set PKG_CONFIG=pkg-config

$ go env GOBIN
C:\test\陈杰\test

$ Get-WinSystemLocale

LCID             Name             DisplayName
----             ----             -----------
1033             en-US            English (United States)

(go env -json also prints the characters in its output.)

[seankhliao]

Looks like it comes from CL 488375 for #58570
The code uses unicode.IsGraphic but checks it on the individual bytes rather than runes, so it fails on multibyte runes like in chinese

	for _, c := range []byte(s) {
		if c == '\r' || c == '\n' || (!unicode.IsGraphic(rune(c)) && !unicode.IsSpace(rune(c))) {

I'm not sure if it's ok to just switch iteration to be runes over a string?

[chenjie199234]

@prattmic @seankhliao @dagood
sorry for the late
my windows language env is chinese and i'm using the chinese name as my windows user name,so the dir path will contain the chinese name.
my terminal is powershell,i tested both in codepage chcp 936,chcp 65001,chcp 437,the chinese characters didn't showed correctly

code page 936

PS C:\Users\陈杰> chcp
活动代码页: 936
PS C:\Users\陈杰> go env
set AR=ar
set CC=gcc
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_ENABLED=1
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set CXX=g++
set GCCGO=gccgo
set GO111MODULE=
set GOAMD64=v1
set GOARCH=amd64
set GOAUTH=netrc
go: stripping unprintable or unescapable characters from %"GOBIN"%
set GOBIN=C:\Users\������\Desktop\Go\bin
go: stripping unprintable or unescapable characters from %"GOCACHE"%
set GOCACHE=C:\Users\������\Desktop\Go\cache
set GOCACHEPROG=
set GODEBUG=
go: stripping unprintable or unescapable characters from %"GOENV"%
set GOENV=C:\Users\������\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFIPS140=off
set GOFLAGS=
go: stripping unprintable or unescapable characters from %"GOGCCFLAGS"%
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\������\AppData\Local\Temp\go-build1782176678=/tmp/go-build -gno-record-gcc-switches
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMOD=NUL
go: stripping unprintable or unescapable characters from %"GOMODCACHE"%
set GOMODCACHE=C:\Users\������\Desktop\Go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
go: stripping unprintable or unescapable characters from %"GOPATH"%
set GOPATH=C:\Users\������\Desktop\Go
set GOPRIVATE=
set GOPROXY=direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=off
set GOTELEMETRY=local
go: stripping unprintable or unescapable characters from %"GOTELEMETRYDIR"%
set GOTELEMETRYDIR=C:\Users\������\AppData\Roaming\go\telemetry
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.24.0
set GOWORK=
set PKG_CONFIG=pkg-config

code page 65001

Active code page: 65001
PS C:\Users\陈杰> go env
set AR=ar
set CC=gcc
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_ENABLED=1
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set CXX=g++
set GCCGO=gccgo
set GO111MODULE=
set GOAMD64=v1
set GOARCH=amd64
set GOAUTH=netrc
go: stripping unprintable or unescapable characters from %"GOBIN"%
set GOBIN=C:\Users\������\Desktop\Go\bin
go: stripping unprintable or unescapable characters from %"GOCACHE"%
set GOCACHE=C:\Users\������\Desktop\Go\cache
set GOCACHEPROG=
set GODEBUG=
go: stripping unprintable or unescapable characters from %"GOENV"%
set GOENV=C:\Users\������\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFIPS140=off
set GOFLAGS=
go: stripping unprintable or unescapable characters from %"GOGCCFLAGS"%
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\������\AppData\Local\Temp\go-build2925785997=/tmp/go-build -gno-record-gcc-switches
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMOD=NUL
go: stripping unprintable or unescapable characters from %"GOMODCACHE"%
set GOMODCACHE=C:\Users\������\Desktop\Go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
go: stripping unprintable or unescapable characters from %"GOPATH"%
set GOPATH=C:\Users\������\Desktop\Go
set GOPRIVATE=
set GOPROXY=direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=off
set GOTELEMETRY=local
go: stripping unprintable or unescapable characters from %"GOTELEMETRYDIR"%
set GOTELEMETRYDIR=C:\Users\������\AppData\Roaming\go\telemetry
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.24.0
set GOWORK=
set PKG_CONFIG=pkg-config

code page 437

PS C:\Users\陈杰> chcp
Active code page: 437
PS C:\Users\陈杰> go env
set AR=ar
set CC=gcc
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_ENABLED=1
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set CXX=g++
set GCCGO=gccgo
set GO111MODULE=
set GOAMD64=v1
set GOARCH=amd64
set GOAUTH=netrc
go: stripping unprintable or unescapable characters from %"GOBIN"%
set GOBIN=C:\Users\������\Desktop\Go\bin
go: stripping unprintable or unescapable characters from %"GOCACHE"%
set GOCACHE=C:\Users\������\Desktop\Go\cache
set GOCACHEPROG=
set GODEBUG=
go: stripping unprintable or unescapable characters from %"GOENV"%
set GOENV=C:\Users\������\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFIPS140=off
set GOFLAGS=
go: stripping unprintable or unescapable characters from %"GOGCCFLAGS"%
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\������\AppData\Local\Temp\go-build3667658653=/tmp/go-build -gno-record-gcc-switches
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMOD=NUL
go: stripping unprintable or unescapable characters from %"GOMODCACHE"%
set GOMODCACHE=C:\Users\������\Desktop\Go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
go: stripping unprintable or unescapable characters from %"GOPATH"%
set GOPATH=C:\Users\������\Desktop\Go
set GOPRIVATE=
set GOPROXY=direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=off
set GOTELEMETRY=local
go: stripping unprintable or unescapable characters from %"GOTELEMETRYDIR"%
set GOTELEMETRYDIR=C:\Users\������\AppData\Roaming\go\telemetry
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.24.0
set GOWORK=
set PKG_CONFIG=pkg-config

[ianlancetaylor]

Does the patch in https://go.dev/cl/651295 fix the problem?

[gopherbot]

Change https://go.dev/cl/651295 mentions this issue: cmd/go: look at runes, not bytes, when printing env vars