runtime/debug: vcs.modified populated in ReadBuildInfo for go install but not go build

[carbocation]

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

$ go version
go version go1.18beta2 darwin/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=""
GOCACHE="/Users/james/Library/Caches/go-build"
GOENV="/Users/james/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/james/go/pkg/mod"
GOOS="darwin"
GOPATH="/Users/james/go"
GOPROXY="direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.18beta2"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/james/projects/debug-module-version-demo/go.mod"
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/g1/r_29t6g17l926yzy2610sy3m0000gn/T/go-build2749357119=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Produce a binary with go build and with go install:

1. Fetch the demo repo from @mark-rushakoff : git clone https://github.com/mark-rushakoff/debug-module-version-demo.git
2. go install
3. go build -o demo.osx *.go

Compare the attached build info:

Output from go build

$ go version -m demo.osx                                     
demo.osx: go1.18beta2
	path	command-line-arguments
	dep	golang.org/x/text	v0.0.0-20170915032832-14c0d48ead0c	h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
	dep	rsc.io/quote	v1.5.2	h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
	dep	rsc.io/sampler	v1.3.0	h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
	build	-compiler=gc
	build	CGO_ENABLED=1
	build	CGO_CFLAGS=
	build	CGO_CPPFLAGS=
	build	CGO_CXXFLAGS=
	build	CGO_LDFLAGS=
	build	GOARCH=amd64
	build	GOOS=darwin
	build	GOAMD64=v1

Output from go install

$ go version -m /Users/james/go/bin/debug-module-version-demo
/Users/james/go/bin/debug-module-version-demo: go1.18beta2
	path	github.com/mark-rushakoff/debug-module-version-demo
	mod	github.com/mark-rushakoff/debug-module-version-demo	(devel)	
	dep	golang.org/x/text	v0.0.0-20170915032832-14c0d48ead0c	h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
	dep	rsc.io/quote	v1.5.2	h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
	dep	rsc.io/sampler	v1.3.0	h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
	build	-compiler=gc
	build	CGO_ENABLED=1
	build	CGO_CFLAGS=
	build	CGO_CPPFLAGS=
	build	CGO_CXXFLAGS=
	build	CGO_LDFLAGS=
	build	GOARCH=amd64
	build	GOOS=darwin
	build	GOAMD64=v1
	build	vcs=git
	build	vcs.revision=f3f34e10b35e88a6f6998d8c1938a5998c33cb64
	build	vcs.time=2018-12-13T20:11:42Z
	build	vcs.modified=true

What did you expect to see?

I expected to see vcs.revision/vcs.modified/etc populated in the runtime/debug.ReadBuildInfo() of the binaries produced by go build -o demo.osx *.go and go install.

What did you see instead?

I saw vcs.revision/vcs.modified/etc populated only in the runtime/debug.ReadBuildInfo() of the binary produced by go install, but not the binary produced by go build -o demo.osx *.go.

[carbocation]

With additional testing, non-population of vcs.revision/etc in runtime/debug.ReadBuildInfo() seems to only affect go build when the specific go files (in this case, *.go) are specified. When they are not specified, the tags are populated as expected.

E.g:

# note *.go not specified
$ go build -o demo.osx
$ go version -m demo.osx                        
demo.osx: go1.18beta2
	path	github.com/mark-rushakoff/debug-module-version-demo
	mod	github.com/mark-rushakoff/debug-module-version-demo	(devel)	
	dep	golang.org/x/text	v0.0.0-20170915032832-14c0d48ead0c	h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
	dep	rsc.io/quote	v1.5.2	h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
	dep	rsc.io/sampler	v1.3.0	h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
	build	-compiler=gc
	build	CGO_ENABLED=1
	build	CGO_CFLAGS=
	build	CGO_CPPFLAGS=
	build	CGO_CXXFLAGS=
	build	CGO_LDFLAGS=
	build	GOARCH=amd64
	build	GOOS=darwin
	build	GOAMD64=v1
	build	vcs=git
	build	vcs.revision=f3f34e10b35e88a6f6998d8c1938a5998c33cb64
	build	vcs.time=2018-12-13T20:11:42Z
	build	vcs.modified=true

So the bug I am reporting may be intended behavior when files are specified, whose description I have just missed in the documentation.

[seankhliao]

Duplicate of #51279