strconv: fmt.Sscanf "0x" "%v" regression in 1.13beta1/tip

[speter]

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

$ go version
go version devel +01d137262a Mon Jul 29 21:07:49 2019 +0000 linux/amd64
go version go1.13beta1 linux/amd64

Does this issue reproduce with the latest release?

Not with stable releases, yes with latest beta.

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/peter/.cache/go-build"
GOENV="/home/peter/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/peter/tmp"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/peter/tmp/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/peter/tmp/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/peter/tmp/go/src/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build986871235=/tmp/go-build -gno-record-gcc-switches"

What did you do?

https://play.golang.org/p/rQsfk3s-_ai

What did you expect to see?

as with stable releases

What did you see instead?

strconv.ParseInt: parsing "0x": invalid syntax

go-gcfg/gcfg#17

[robpike]

It's not clear to me that it's a regression so much as catching a previously missed error. "0x" is indeed invalid syntax.

[andybons]

Thanks for the issue.

0x is in fact invalid syntax. 1.13 has just made it more strict. I’m going to close this issue. If you feel this is in error then please comment.