Please answer these questions before submitting your issue. Thanks!

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

go version go1.10.2 linux/amd64
go version devel +06b326054d Sat Jun 2 18:00:44 2018 +0000 linux/amd64

vgo version:

$ (command cd $(go list -f "{{.Dir}}" golang.org/x/vgo); git rev-parse HEAD)
7c0cf33f39ccf5d8e4c59d34a150425ddac7df6a

Does this issue reproduce with the latest release?

Yes, and tip.

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/home/myitcv/.cache/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/tmp/tmp.08BtAFjstf"
GOPROXY=""
GORACE=""
GOROOT="/home/myitcv/gos"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
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-build089678844=/tmp/go-build -gno-record-gcc-switches"
VGOMODROOT=""

What did you do?

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

cd `mktemp -d`
export GOPATH=$PWD
mkdir hello
cd hello
cat <<EOD > go.mod
module example.com/hello
EOD
vgo list .

What did you expect to see?

Something like:

{
        "Module": {
                "Top": true,
                "Path": "example.com/hello",
                "Version": ""
        }
}

What did you see instead?

vgo: import "example.com/hello" [/tmp/tmp.08BtAFjstf/hello]: no Go source files

As I understand it, there is no requirement for a Go module to contain source code; it could just be a parent of submodules.

I wonder whether this issue could/should be broadened to be "fully define semantics of vgo list" to include:

• the fact vgo list should work where there are no source files
• vgo list -t, or some super-powers version of it, should give one the ability to list versions across all major version numbers (because otherwise I need to know the latest major version number to do vgo list -t example.com/hello/vX
• adding the -deps and -test flags from tip
• whether vgo list should ever create a go.mod if it doesn't exist
• whether vgo list should have a mode which doesn't try to do any resolution/downloading and instead errors in case something doesn't fully resolve, so that tools depending on its output don't block for potentially long periods of time, or barf on non-JSON output
• .... others?