x/sys/unix: ./mkall.sh failes with readlink: illegal option -- f

[darkLord19]

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

go version go1.13.4 darwin/amd64

Does this issue reproduce with the latest release?

yes

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/uparmar/Library/Caches/go-build"
GOENV="/Users/uparmar/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/Users/uparmar/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.13.4/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.13.4/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="0"
GOMOD="/Users/uparmar/Development/sys/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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/l7/x5hcvngd5m99k62kxv7srrdr0000gn/T/go-build301769780=/tmp/go-build -gno-record-gcc-switches"

What did you do?

export GOOS=linux
export GOARCH=amd64
./mkall.sh from sys/unix directory.

What did you expect to see?

No error

What did you see instead?

readlink: illegal option -- f
usage: readlink [-n] [file ...]
docker: Error response from daemon: create .: volume name is too short, names should be at least two alphanumeric characters.

[darkLord19]

darwin readlink doesn't support -f option.

[gopherbot]

Change https://golang.org/cl/210157 mentions this issue: unix: add alternate working method to get dirname for darwin