x/exp/slog: does not build with 1.18

[imle]

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

$ go version
go version go1.18.8 darwin/arm64

Does this issue reproduce with the latest release?

No, it works fine in 1.19

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

go env Output

$ go env
GO111MODULE=""
GOARCH="arm64"
GOBIN=""
GOCACHE="/Users/simle/Library/Caches/go-build"
GOENV="/Users/simle/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/simle/Development/go/pkg/mod"
GONOPROXY="git.sqcorp.co,git.corp.squareup.com,github.com/squareup"
GONOSUMDB="git.sqcorp.co,git.corp.squareup.com,github.com/squareup"
GOOS="darwin"
GOPATH="/Users/simle/Development/go"
GOPRIVATE="git.sqcorp.co,git.corp.squareup.com,github.com/squareup"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/homebrew/Cellar/go@1.18/1.18.8/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/homebrew/Cellar/go@1.18/1.18.8/libexec/pkg/tool/darwin_arm64"
GOVCS=""
GOVERSION="go1.18.8"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/dev/null"
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 arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/dj/8r2z_93n6h79603f18pcf1880000gn/T/go-build3340641431=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I tried to import and use the package golang.org/x/exp/slog and ran into the issue of atomic.Int64 not being defined for 1.18.

What did you expect to see?

The go.mod file in the exp repo shows that it should work for 1.18.

What did you see instead?

Failure to build.

[randall77]

@jba

[jba]

Since this package is an experimental implementation for something that will be in Go 1.2X, we don't feel that it needs to work on 1.18.

Is there a compelling reason you need it for 1.18?

[imle]

No worries, wanted to try it out and am currently stuck with 1.18. I was making the assumption that it would work with that version based on the go.mod file and since it was just the one reference to atomic that was preventing it, that it might be worth enabling it by using atomic.Value instead.