runtime/debug: BuildInfo does not honour replace directives

[myitcv]

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

$ go version
go version devel +1cd724acb6 Tue Feb 18 20:21:35 2020 +0000 linux/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN="/tmp/tmp.iN3J3OviqO/bin"
GOCACHE="/home/myitcv/.cache/go-build"
GOENV="/home/myitcv/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/tmp/tmp.YATmfepfQp"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/myitcv/gos"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/tmp/tmp.iN3J3OviqO/go.mod"
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build497027281=/tmp/go-build -gno-record-gcc-switches"

What did you do?

export GOPATH=$(mktemp -d) 
cd $(mktemp -d) 
export GOBIN=$PWD/bin
go mod init example.com/hello
go get -d github.com/myitcvscratch/main1@v0.0.0-20200223195030-0e559444dd31
go install github.com/myitcvscratch/main1
./bin/main1

gives:

Hello

and:

go version -m ./bin/main1

gives:

./bin/main1: devel +1cd724acb6 Tue Feb 18 20:21:35 2020 +0000
        path    github.com/myitcvscratch/main1
        mod     github.com/myitcvscratch/main1  v0.0.0-20200223195030-0e559444dd31      h1:ksuMuyNXJTVEqPoCW7OFo0yey/ijEj3Rxt56WwUPbD4=

Then:

go mod edit -replace=github.com/myitcvscratch/main1=github.com/myitcvscratch/main2@v0.0.0-20200223200030-a2adf1d5f0a7
go install github.com/myitcvscratch/main1
./bin/main1

gives:

Goodbye

But:

go version -m ./bin/main1

gives:

./bin/main1: devel +1cd724acb6 Tue Feb 18 20:21:35 2020 +0000
        path    github.com/myitcvscratch/main1
        mod     github.com/myitcvscratch/main1  v0.0.0-20200223195030-0e559444dd31      h1:ksuMuyNXJTVEqPoCW7OFo0yey/ijEj3Rxt56WwUPbD4=

i.e. the newly built binary does not include any information about the fact that github.com/myitcvscratch/main1 has been replaced, nor is any information about github.com/myitcvscratch/main2 included in the runtime/debug.BuildInfo

What did you expect to see?

Some reflection of the fact that github.com/myitcvscratch/main1 has been replaced with github.com/myitcvscratch/main2 in the runtime/debug.BuildInfo

What did you see instead?

As above

cc @bcmills @jayconrod @hyangah

[bcmills]

This is closely related to #33975, in that modload.PackageBuildInfo is confusing “the main module” with “the module containing package main”. (There is no point in checking for a replacement for “the main module” because it cannot be replaced. However, we should check for a replacement for the module containing package main, because it is not necessarily the main module proper.)

CC @matloob

[bcmills]

This turned out to be easy enough to just go ahead and fix.

[gopherbot]

Change https://golang.org/cl/220645 mentions this issue: cmd/go/internal/modload: record the replacement for the module containing package main in BuildInfo

[gopherbot]

Change https://golang.org/cl/220717 mentions this issue: cmd/go: add GOEXE suffix in TestScript/version_replace

[gopherbot]

Change https://golang.org/cl/220898 mentions this issue: Revert "Revert "cmd/go/internal/modload: record the replacement for the module containing package main in BuildInfo""