go/constant: complex != unknown violates Compare contract #75137
Description
Go version
go version go1.26-devel_a21249436b 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/Andrei.Efanov/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/Andrei.Efanov/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/h0/j2mhh5tx4cdcn_2n79qqbcg40000kt/T/go-build2822157088=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/Andrei.Efanov/Projects/chore/go/src/go.mod'
GOMODCACHE='/Users/Andrei.Efanov/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/Andrei.Efanov/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/Andrei.Efanov/Projects/chore/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/Andrei.Efanov/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/Andrei.Efanov/Projects/chore/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.26-devel_a21249436b Mon Aug 25 02:31:40 2025 -0700'
GOWORK=''
PKG_CONFIG='pkg-config'What did you do?
Run the following code:
package main
import (
"fmt"
"go/constant"
"go/token"
)
func main() {
x := constant.MakeUnknown()
y := constant.MakeImag(constant.MakeFloat64(1.2))
fmt.Println("x != y:", constant.Compare(x, token.NEQ, y))
}What did you see happen?
The output:
x != y: true
What did you expect to see?
The Compare godoc says:
If one of the operands is [Unknown], the result is false.
The output must be:
x != y: false