Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

cmd/go: go list -m reports command-line-arguments when called outside a module #36793

Open
perillo opened this issue Jan 27, 2020 · 3 comments
Open

Comments

@perillo
Copy link

@perillo perillo commented Jan 27, 2020

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

$ go version
go version go1.14beta1 linux/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="on"
GOARCH="amd64"
GOBIN="/home/manlio/.local/bin"
GOCACHE="/home/manlio/.cache/go-build"
GOENV="/home/manlio/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY="github.com/perillo"
GONOSUMDB="github.com/perillo"
GOOS="linux"
GOPATH="/home/manlio/.local/lib/go:/home/manlio/src/go"
GOPRIVATE="github.com/perillo"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/manlio/sdk/go1.14beta1"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/manlio/sdk/go1.14beta1/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
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-build475655411=/tmp/go-build -gno-record-gcc-switches"
GOROOT/bin/go version: go version go1.14beta1 linux/amd64
GOROOT/bin/go tool compile -V: compile version go1.14beta1
uname -sr: Linux 5.4.15-arch1-1
/usr/lib/libc.so.6: GNU C Library (GNU libc) stable release version 2.30.
gdb --version: GNU gdb (GDB) 8.3.1

What did you do?

In a directory with no reachable go.mod:

go list -m -json

What did you expect to see?

go list should report an error, since there is no module.

What did you see instead?

{
	"Path": "command-line-arguments",
	"Main": true
}

This really feels wrong for me.

@bcmills bcmills added this to the Unplanned milestone Jan 27, 2020
@bcmills

This comment has been minimized.

Copy link
Member

@bcmills bcmills commented Jan 27, 2020

Per https://tip.golang.org/cmd/go/#hdr-Package_lists_and_patterns:

As a special case, if the package list is a list of .go files from a single directory, the command is applied to a single synthesized package made up of exactly those files, ignoring any build constraints in those files and ignoring any other files in the directory.

Running a small .go source file (or a small list of files) that has no dependencies outside of the standard library is one of the most common use-cases for the go command outside of a module, and is one of the only operations you can do when outside of a module.

The effective package path for a list of .go source files has been command-line-arguments since well before module mode, and (for every module except std) the module path is a prefix of the package path. That is why go list -m reports that module path: command-line-arguments is the only supported path in that context.

I think @jayconrod recently suggested that we consider also making go run . work when outside of a module. If we decide to do that (and if we can decide what the package path should be in that case), then perhaps we should also reconsider what the output of go list -m should be when outside of a module.

(CC @matloob)

@perillo

This comment has been minimized.

Copy link
Author

@perillo perillo commented Jan 27, 2020

Sorry, I forgot to report that there are no files in the current working directory.

In my case, there is no go.mod file and no .go files. Moreover I ran go list -m, where the package list is empty. In this case the documentation says:

If no import paths are given, the action applies to the package in the current directory.

But there is no package, in my case.

@perillo

This comment has been minimized.

Copy link
Author

@perillo perillo commented Feb 2, 2020

https://github.com/golang/go/blob/master/doc/modules.md#resolving-a-package-to-a-module says that:

At least one file with the .go extension must be present in a directory for it to be considered a package.

And go list fails with

go: cannot find main module
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Linked pull requests

Successfully merging a pull request may close this issue.

None yet
2 participants
You can’t perform that action at this time.