cmd/go: `go list` prints unexpected compiler output for non-stale targets

bcmills commented 2 years ago

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

~/x/tools$ gotip version
go version devel go1.20-867babe1b1 Fri Oct 21 16:23:01 2022 +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

~/x/tools$ gotip env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/usr/local/google/home/bcmills/.cache/go-build"
GOENV="/usr/local/google/home/bcmills/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/usr/local/google/home/bcmills/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/usr/local/google/home/bcmills"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/google/home/bcmills/sdk/gotip"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/google/home/bcmills/sdk/gotip/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="devel go1.20-867babe1b1 Fri Oct 21 16:23:01 2022 +0000"
GCCGO="/usr/local/google/home/bcmills/bin/gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="c++"
CGO_ENABLED="1"
GOMOD="/usr/local/google/home/bcmills/x/tools/go.mod"
GOWORK=""
CGO_CFLAGS="-O2 -g"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-O2 -g"
CGO_FFLAGS="-O2 -g"
CGO_LDFLAGS="-O2 -g"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build3491113060=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Use go install to build a binary in a way that produces output to stdout or stderr, then go list -json=Stale to verify that that binary is not, in fact, stale.

What did you expect to see?

Compiler output from go install and go build, and no compiler output from go list (unless, perhaps, the -export or -compiled flag is set).

What did you see instead?

The go list command, with neither -export nor -compiled repeats all of the stdout / stderr output from the compiler for the go install command, even though it should have no possibility of actually running the compiler!

``` ~/x/tools$ gotip install -gcflags=-m ./cmd/goyacc # golang.org/x/tools/cmd/goyacc cmd/goyacc/yacc.go:138:6: can inline ASSOC cmd/goyacc/yacc.go:140:6: can inline PLEVEL cmd/goyacc/yacc.go:142:6: can inline TYPE cmd/goyacc/yacc.go:145:6: can inline SETASC cmd/goyacc/yacc.go:147:6: can inline SETPLEV cmd/goyacc/yacc.go:149:6: can inline SETTYPE cmd/goyacc/yacc.go:166:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:167:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:168:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:169:14: inlining call to flag.BoolVar … ~/x/tools$ gotip list -gcflags=-m -json=Stale ./cmd/goyacc # golang.org/x/tools/cmd/goyacc cmd/goyacc/yacc.go:138:6: can inline ASSOC cmd/goyacc/yacc.go:140:6: can inline PLEVEL cmd/goyacc/yacc.go:142:6: can inline TYPE cmd/goyacc/yacc.go:145:6: can inline SETASC cmd/goyacc/yacc.go:147:6: can inline SETPLEV cmd/goyacc/yacc.go:149:6: can inline SETTYPE cmd/goyacc/yacc.go:166:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:167:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:168:16: inlining call to flag.StringVar cmd/goyacc/yacc.go:169:14: inlining call to flag.BoolVar … {} ```

I noticed this existing bug while reviewing CL 444619 (CC @matloob)

bcmills commented 2 years ago

This bug was likely introduced in CL 128903, which fixed #23877.

bcmills commented 2 years ago

The condition that controls whether we would actually run the compiler appears to be here: https://cs.opensource.google/go/go/+/master:src/cmd/go/internal/work/exec.go;l=476-479;drc=01604129aee8bfc9dd3e2fffd2ad8f772a3089ec

gopherbot commented 2 years ago

Change https://go.dev/cl/444836 mentions this issue: cmd/go: don't print cached output for non-build list commands

golang / go