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

Jump to bottom

cmd/go: 'go mod why -m' gives false negative in inconsistent, pruned module #48613

Closed
jayconrod opened this issue Sep 24, 2021 · 1 comment
Closed

cmd/go: 'go mod why -m' gives false negative in inconsistent, pruned module #48613

jayconrod opened this issue Sep 24, 2021 · 1 comment
Labels
FrozenDueToAge modules NeedsFix The path to resolution is known, but the work has not been done.
Milestone
Backlog

Comments

@jayconrod
Copy link
Contributor

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

$ go version
go version go1.17.1 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=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/jay/.cache/go-build"
GOENV="/home/jay/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/jay/.cache/gomodcache"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/jay/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/go/go1.17.1"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/go/go1.17.1/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.17.1"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/jay/Code/test/go.mod"
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-build3259942741=/tmp/go-build -gno-record-gcc-switches"

What did you do?

In a tidy pruned module (with go 1.17 or higher in go.mod), edit an indirect dependency down to a lower version without changing direct dependencies that require it. This makes go.mod inconsistent: go list -m all will show an error, and go -list -m -mod=mod all will show the original build list and will fix go.mod.

In this state, go mod why -m falsely reports that the main module does not depend on the downgraded module.

# This command works correctly.
go mod why -m rsc.io/sampler

# Downgrade indirect dependency without changing direct dependent.
go mod edit -require=rsc.io/sampler@v1.2.0

# This command says nothing uses rsc.io/sampler
go mod why -m rsc.io/sampler

-- go.mod --
module use

go 1.17

require rsc.io/quote v1.5.2

require (
        golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c // indirect
        rsc.io/sampler v1.3.0 // indirect
)
-- go.sum --
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
rsc.io/quote v1.5.2 h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0=
rsc.io/sampler v1.3.0 h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
-- use.go --
package use

import _ "rsc.io/quote"

What did you expect to see?

go mod why -m rsc.io/sampler should report the correct import chain in either case.

What did you see instead?

# rsc.io/sampler
(main module does not need module rsc.io/sampler)
@jayconrod jayconrod added NeedsFix The path to resolution is known, but the work has not been done. modules labels Sep 24, 2021
@jayconrod jayconrod added this to the Backlog milestone Sep 24, 2021
@gopherbot
Copy link

Change https://golang.org/cl/352115 mentions this issue: cmd/go: make 'go mod why -m' work in inconsistent, pruned module

@golang golang locked and limited conversation to collaborators Sep 24, 2022
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Assignees
No one assigned
Labels
FrozenDueToAge modules NeedsFix The path to resolution is known, but the work has not been done.
Projects
None yet
Milestone
Backlog
Development

No branches or pull requests
2 participants
@jayconrod @gopherbot