cmd/compile: -gcflags="-m=2 -d=ssa/check_bce/debug=1" sometimes results in no output

[RaduBerinde]

Go version

go version go1.24.3 darwin/arm64

Output of go env in your module/workspace:

AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE='on'
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/radu/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/radu/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/x0/5yrxw_4s271g705vjscld23c0000gq/T/go-build680255877=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/radu/go/src/github.com/cockroachdb/pebble/go.mod'
GOMODCACHE='/Users/radu/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/radu/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.darwin-arm64'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/radu/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.darwin-arm64/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.24.3'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

In the Pebble (github.com/cockroachdb/pebble) master branch:

go build -gcflags="-m=2 -d=ssa/check_bce/debug=1" ./sstable/colblk

Note that we use this output (through github.com/jordanlewis/gcassert) for a linter that verifies that certain known hot paths are inlined.

What did you see happen?

The command outputs nothing.

What did you expect to see?

In go1.24.2 or older, I get a ton of information: https://gist.github.com/RaduBerinde/87145c7327fdf035de9a0008f4d841c5

[RaduBerinde]

Ah, interestingly go build -gcflags="-m=2" ./sstable/colblk seems to work. Maybe that -d flag is no longer valid? Seems like there should be some error output though.

[RaduBerinde]

This is very strange.. but after running the variant above, the original variant started working..

[gabyhelp]

Related Issues

• go tool compile #55111 (closed)
• cmd/go/internal/work/security.go: invalid flag in `#cgo LDFLAGS: -Wl,-rpath,.` #70924 (closed)
• go build #52634 (closed)
• cmd/go : "-gcflags -S" doesn't work when binary is present #26884 (closed)
• cmd/go/internal/work/security.go: invalid flag in `#cgo darwin LDFLAGS: -Wl,-rpath -Wl,@loader_path` #70923 (closed)
• cmd/go: go env -changed prints changed values for variables in go.env #67542 (closed)
• Test #67906 (closed)
• cmd/go: 1.8beta2 cross compilation fails without CGO_ENABLED=0 #18360 (closed)
• run #70024 (closed)
• sb #53220 (closed)

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

[mknyszek]

CC @golang/compiler

[mknyszek]

In triage we think this might be a caching issue. Something is getting cached and the output isn't getting cached and reprinted... or something.