testing: -run empty regex for first test not working

[santhosh-tekuri]

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

$ go version
go version go1.10.3 windows/amd64

Does this issue reproduce with the latest release?

dont know

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

go env Output

$ go env
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\rajag\AppData\Local\go-build
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=C:\Users\rajag\go
set GORACE=
set GOROOT=C:\Installations\Go
set GOTMPDIR=
set GOTOOLDIR=C:\Installations\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\rajag\AppData\Local\Temp\go-build546518454=/tmp/go-bu
ild -gno-record-gcc-switches

What did you do?

trying to use empty regex for begining of subtest path

$ go test -run /leader/quorumWait/unreachable
testing: warning: no tests to run
PASS
ok      github.com/santhosh-tekuri/raft 0.064s

$ go test -run Raft/leader/quorumWait/unreachable
PASS
ok      github.com/santhosh-tekuri/raft 2.362s

What did you expect to see?

with empty regex, the test should be run

What did you see instead?

with empty regex, it says "no tests to run"
with non empty regex, it runs the test

[santhosh-tekuri]

closing. as in my case i dont have any top level tests.
and it is behaving as documented