Go package coverage is calculated inconsistently in 1.22.5

[tehaksbrid]

Go version

1.22.5

Output of go env in your module/workspace:

set GO111MODULE=on
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\{username}\AppData\Local\go-build
set GOENV=C:\Users\{username}\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\{username}\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\zluka\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=C:/Program Files/Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.22.5
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 -ffile-prefix-map=C:\Users\{username}\AppData\Local\Temp\go-build2959683362=/tmp/go-build -gno-record-gcc-switches

What did you do?

When producing test coverage via go test -cover ./..., incorrect package summary coverage values are generated. This can be confirmed by generating coverprofiles and inspecting those.

This issue is only present in 1.22.5. Other versions summarize package coverage correctly. I have reproduced this in a working demo here.

What did you see happen?

Running make coverage-browser for with Go version 1.22.5 on the above repo yields the following coverage summary:

go test -cover -coverprofile=cover.txt ./...
?       golang-coverage-disagreement-demo/applications/packages/bar     [no test files]
        golang-coverage-disagreement-demo/applications/packages/baz             coverage: 0.0% of statements
ok      golang-coverage-disagreement-demo/applications/foo      1.098s  coverage: 75.0% of statements
go tool cover -html=cover.txt


### What did you expect to see?

Package `foo` should show 100% coverage, as it does in 1.21.12.

[gabyhelp]

Related Issues and Documentation

• cmd/cover: regression in 1.20, cover tool no longer includes packages without tests #58770 (closed)
• cmd/go: -coverpkg=all gives different coverage value when run on a package list vs ./... #23883 (closed)
• Coverage incorrectly reported as 100% ( go test cover) #26760 (closed)
• cmd/go: go 1.22.0 inconsistent and variable code coverage output for the same folder #65570 (closed)
• testing: Coverage() returns different values in 1.21 than 1.19.X #62212
• cmd/go: duplicate lines in coverage file after update to 1.22 #65636
• cmd/go: go test -cover & go test -coverprofile should always output a coverage #24570 (closed)
• cmd/go: test -cover reports 100.0% without full coverage #39168
• cmd/go: go 1.22.0: go test throws errors when processing folders not listed in coverpkg argument #65653 (closed)
• cmd/covdata: percent does not support -coverpkg #66464

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

See the -coverpkg flag.