cmd/go: test -coverprofile "path too long" error on Windows

[chrisdutz]

What version of Go are you using (go version)?

$ go version

go version go1.20.5 windows/amd64

Does this issue reproduce with the latest release?

I am on the latest release

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GO111MODULE=

set GOARCH=amd64

set GOBIN=

set GOCACHE=C:\Users\cdutz\AppData\Local\go-build

set GOENV=C:\Users\cdutz\AppData\Roaming\go\env

set GOEXE=.exe

set GOEXPERIMENT=

set GOFLAGS=

set GOHOSTARCH=amd64

set GOHOSTOS=windows

set GOINSECURE=

set GOMODCACHE=C:\Users\cdutz\go\pkg\mod

set GONOPROXY=

set GONOSUMDB=

set GOOS=windows

set GOPATH=C:\Users\cdutz\go

set GOPRIVATE=

set GOPROXY=https://proxy.golang.org,direct

set GOROOT=C:\Users\cdutz.mvnGoLang\go1.20.5.windows-amd64

set GOSUMDB=sum.golang.org

set GOTMPDIR=

set GOTOOLDIR=C:\Users\cdutz.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64

set GOVCS=

set GOVERSION=go1.20.5

set GCCGO=gccgo

set GOAMD64=v1

set AR=ar

set CC=gcc

set CXX=g++

set CGO_ENABLED=0

set GOMOD=NUL

set GOWORK=

set CGO_CFLAGS=-O2 -g

set CGO_CPPFLAGS=

set CGO_CXXFLAGS=-O2 -g

set CGO_FFLAGS=-O2 -g

set CGO_LDFLAGS=-O2 -g

set PKG_CONFIG=pkg-config

set GOGCCFLAGS=-m64 -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=C:\Users\cdutz\AppData\Local\Temp\go-build1515085630=/tmp/go-build -gno-record-gcc-switches

What did you do?

We are using go in the Apache PLC4X project in the plc4go sub-project.
When running our build in our CI/CD servers, the Windows builds are failing when running the tests with coverage:

[WARNING] ---------Exec.Err--------- [WARNING] github.com/apache/plc4x/plc4go/protocols/cbus/readwrite/model: C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: fork/exec C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: Der Dateiname oder die Erweiterung ist zu lang.

Path length is too long (Got a German Windows)

So even when executing the command:

go test -v -coverprofile=target/coverage.out ./...

I'm getting the same error, so it's not related to the maven plugin, that we are using.
I even tried moving Go to "C:\Go" but this too didn't help.

For now we're just disabling go coverage on all windows machines, but we'd like to enable it again.

What did you expect to see?

I would expect the build to not fail on windows

What did you see instead?

[WARNING] ---------Exec.Err--------- [WARNING] github.com/apache/plc4x/plc4go/protocols/cbus/readwrite/model: C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: fork/exec C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: Der Dateiname oder die Erweiterung ist zu lang.

[sruehl]

To add on the last section "What did you see instead":

$ go test -v -coverprofile=target/coverage.out ./... > build.log
github.com/apache/plc4x/plc4go/protocols/cbus/readwrite/model: C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: fork/exec C:\Users\cdutz\.mvnGoLang\go1.20.5.windows-amd64\pkg\tool\windows_amd64\cover.exe: Der Dateiname oder die Erweiterung ist zu lang.

[chrisdutz]

So let me explain what my colleague wanted to provide you with ;-)

So right now whenever Maven detects that it's running on a windows system, we now simply replace the flag: "-coverprofile=target/coverage.out" with a second "-v" (the tool doesn't like empty flags therefore we're just using a double "-v").

[thanm]

Thanks for the report, I'll take a look.

[thanm]

A request: if you could please run one of the failing commands with "-x -work" flags in addition and post the output, that would be helpful for me so as to determine which path it is that is over the limit. E.g. output of

go test -x -work -v -coverprofile=target/coverage.out ./...

Thanks.

[chrisdutz]

Hope this helps (a bit large)

build.log

[thanm]

Thanks, yes, that is helpful. It looks as though the issue is with total command line length, not with the length of any specific file being passed to the cover tool. I'll see about crafting a fix.

[chrisdutz]

I have seen something similar with other tools ... there the length of the command being executed was too long ... they resolved the issue with dynamically creating some sort of batch script, that then is simply called (Not pretty, but it worked)

[thanm]

We have machinery already to handle this for the compiler and the assembler, I just need to update the cover tool to use the same facilities. Will send a CL later today.

[chrisdutz]

Oh wow ... great :-) Thank you so much :-)

[gopherbot]

Change https://go.dev/cl/503735 mentions this issue: cmd/{go,cover}: enable response file args for cmd/cover