golang/go

cmd/go: reject 'go generate' on packages in unreplaced module dependencies?

Open

#29,751 opened on Jan 15, 2019

View on GitHub
 (5 comments) (1 reaction) (0 assignees)Go (19,008 forks)batch import
GoCommandNeedsFixhelp wantedmodules

Repository metrics

Stars
 (133,883 stars)
PR merge metrics
 (No merged PRs in 30d)

Description

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

Does this issue reproduce with the latest release?

Testing with the beta pre the 1.12 release.

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

What did you do?

Ran testscript on the following:

go generate fruit.com/fruit

-- go.mod --
module mod

require fruit.com v1.0.0

-- main.go --
package main

func main() {
}

-- .gomodproxy/fruit.com_v1.0.0/.mod --
module fruit.com

-- .gomodproxy/fruit.com_v1.0.0/.info --
{"Version":"v1.0.0","Time":"2018-10-22T18:45:39Z"}

-- .gomodproxy/fruit.com_v1.0.0/go.mod --
module fruit.com

-- .gomodproxy/fruit.com_v1.0.0/fruit/fruit.go --
package fruit

//go:generate bash -c "echo 'package fruit' > something.go"

What did you expect to see?

A failed run.

What did you see instead?

> go generate fruit.com/fruit
[stderr]
go: finding fruit.com v1.0.0
go: downloading fruit.com v1.0.0
go: extracting fruit.com v1.0.0
go: not generating in packages in dependency modules

PASS

It feels like this should be an error instead of a noisy success. Reason being, I've specified the pattern of a non-main module package(s) on the command line; based on the current implementation, that will never succeed (even if there is a replace directive).

cc @bcmills.

Contributor guide

Research direction
Investigate how 'go generate' currently handles patterns that match packages in non main modules. The issue suggests that when a pattern matches a package in a dependency module, 'go generate' silently does nothing rather than reporting an error. Look at the generate command's implementation in the Go source code (src/cmd/go/) and understand where it decides to skip packages. Propose a change to return an error when the user explicitly specifies a package pattern that resides in a non main module, as the operation will never succeed.
Tech stack
go
Domain
backendcli
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
GoGo modules
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75