go get or go build does not work for repo

[rhnvrm]

Describe the bug
As mentioned in https://github.com/google/cel-go#install

go mod init <my-cel-app>
go build ./...

or

go get -u github.com/google/cel-go/...

Does not work and results in the following error:

go build -o myproj.bin -v
go: finding github.com/google/cel-go/interpreter/functions latest
go: finding github.com/google/cel-go/common/types latest
go: finding github.com/google/cel-go/cel latest
go: finding github.com/google/cel-go/common/types/ref latest
go: finding github.com/google/cel-go/checker/decls latest
go: finding github.com/google/cel-go/interpreter latest
go: finding github.com/google/cel-go/common latest
Fetching https://github.com?go-get=1
go: finding github.com/google/cel-go/checker latest
Parsing meta tags from https://github.com?go-get=1 (status code 200)
build company.tech/rhnvrm/myproj cannot load github.com/google/cel-go/cel: cannot find module providing package github.com/google/cel-go/cel

go get -u github.com/google/cel-go/...
...
go: github.com/golang/lint@v0.0.0-20190313153728-d0100b6bd8b3: parsing go.mod: unexpected module path "golang.org/x/lint"

To fix this for now, I have done a git clone and added a replace directive

This is my go.mod

module company.tech/rhnvrm/myproj

go 1.12

require (
	github.com/golang/protobuf v1.3.0
	github.com/google/cel-go v0.2.0
	google.golang.org/genproto v0.0.0-20190227213309-4f5b463f9597
)

replace github.com/google/cel-go v0.2.0 => ./celgo

[TristonianJones]

Interesting, I tried this yesterday. Will give it a look. Thanks for the report.

[lopezator]

I think the issue isn't in cel-go itself but in:

golang/lint#436

See:

https://github.com/ory/hydra/blob/master/go.mod#L86-L87

[TristonianJones]

I did notice that the lack of a go.mod in the cel-spec repo was causing both a pinned and latest version of the deps for cel-go to be included in the go get -u ... command. I'll see pinning the deps on cel-spec helps later today.

[lopezator]

@TristonianJones I think that installing via go get -u isn't a good practice in go modules aware project, see:

https://github.com/golang/go/wiki/Modules#how-to-upgrade-and-downgrade-dependencies

go get github.com/google/cel-go@latest or go get github.com/google/cel-go would fetch latest tag (v0.2.0).

go get github.com/google/cel-go@master would fetch latest commit.

I think that simply removing the -u flag would suffice and is the safest.

[TristonianJones]

Thanks for the tip. I'll update the README

[lopezator]

If you want to add intructions for a modules install I would do:

1. go mod init my-cel-project to initialize a go.mod file.
2. go get github.com/google/cel-go to track the latest cel-go tag (v0.2.0) into your go.mod file.
3. go install github.com/google/cel-go/... to install it.

[lopezator]

Install instructions are still confusing, supposing, for example:

1. mkdir test
2. cd test
3. go mod init test

a) go build ./... after go mod init test does nothing.

go: warning: "./..." matched no packages

b) go get github.com/google/cel-go/... also doesn't.

go get github.com/google/cel-go/...: no matching versions for query "latest"

[rhnvrm]

@TristonianJones, @lopezator, thanks for solving this issue :)

Just tested it, although I think a minor release will be needed, until then in case anyone has the same problem and reaches this page, go get github.com/google/cel-go@master needs to be done to use cel-go.