cmd/go: `mod vendor` tries to evaluate go:embed pattern inside _test.go files

[wizardishungry]

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

$ go version
go version go1.21.1 darwin/arm64

Does this issue reproduce with the latest release?

I don't know.

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

go env Output

$ go env
GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/jon/Library/Caches/go-build'
GOENV='/Users/jon/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/jon/.asdf/installs/golang/1.21.1/packages/pkg/mod'
GONOPROXY='bitbucket.org/thetalake'
GONOSUMDB='bitbucket.org/thetalake'
GOOS='darwin'
GOPATH='/Users/jon/.asdf/installs/golang/1.21.1/packages'
GOPRIVATE='bitbucket.org/thetalake'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/jon/.asdf/installs/golang/1.21.1/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/jon/.asdf/installs/golang/1.21.1/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.21.1'
GCCGO='gccgo'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/jon/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/4y/nhc3l04n53x2125plghk78bw0000gp/T/go-build3701474416=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

1. Import a package containing go:embed directives inside a _test.go file.

import _ "github.com/emiago/sipgo"

For example, https://github.com/emiago/sipgo/blob/main/server_integration_test.go#L26 contains go:embed directives that will not satisfied.

2. Run go mod vendor:

What did you expect to see?

go mod vendor completes normally

What did you see instead?

go: pattern testdata/certs/client.crt: no matching files found

[seankhliao]

working as intended. vendor aims to make it possible to both build and run tests for your dependencies (go test all)

[wizardishungry]

@seankhliao The go:embed I mentioned is included in the vendored package's test code. The go mod vendor documentation says:

Vendor resets the main module's vendor directory to include all packages
needed to build and test all the main module's packages.
It does not include test code for vendored packages.

(Emphasis mine) It's fine if this isn't going to get fixed, but go mod vendor absolutely does not include _test files.

[seankhliao]

Sorry, I misremembered.

cc @bcmills

[quantonganh]

So, according to the go help mod vendor:

$ go help mod vendor
usage: go mod vendor [-e] [-v] [-o outdir]

Vendor resets the main module's vendor directory to include all packages
needed to build and test all the main module's packages.
It does not include test code for vendored packages.

We should not include embed patterns in test files when vendoring? cc @matloob

[gopherbot]

Change https://go.dev/cl/534495 mentions this issue: modcmd: do not copy test embed files when vendoring

[gopherbot]

Change https://go.dev/cl/534376 mentions this issue: modcmd: do not copy test embed files when vendoring