cmd/go: Module mode doesn't turn on automatically while build upon relative path

[JBrVJxsc]

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

$ go version
go version go1.13 darwin/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="/Users/FOOBAR/Library/Caches/go-build"
GOENV="/Users/FOOBAR/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/FOOBAR/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/gs/5npvnn7x1s75tnbcx020t_yr000r7f/T/go-build967562719=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

go mod init // convert the project to the module-based
go build ./src/cli/project/" // from a relative directory. ./src/cli/project isn't in GOPATH (that's why I'm using module).

What did you expect to see?

It should build successfully via module mode.
(If go build directly in the project folder it will detect the go.mod file and use module mode to build successfully)

What did you see instead?

src/cli/project/main.go:4:2: cannot find package "project/cmd" in any of:
/usr/local/go/src/project/cmd (from $GOROOT)
/Users/FOOBAR/go/src/project/cmd (from $GOPATH)

[bcmills]

Please provide concrete steps to reproduce the problem. Specifically, please provide the exact commands run, including any cd commands, and a minimal set of source files.

Note that the go command locates the go.mod file based on its current working directory, not on the directory containing the requested packages — if the go.mod file is in a subdirectory of the current working directory, then the go command will not be able to locate it.

[MHBauer]

Note that the go command locates the go.mod file based on its current working directory, not on the directory containing the requested packages — if the go.mod file is in a subdirectory of the current working directory, then the go command will not be able to locate it.

My understanding reading this is: I must call go build in the directory containing the go.mod file. Is this in the documentation somewhere?

This is surprising to me. Is there a flag to give to go build so it does a cd into the directory before running?

[bcmills]

I must call go build in the directory containing the go.mod file. Is this in the documentation somewhere?

https://golang.org/cmd/go/#hdr-The_main_module_and_the_build_list

Is there a flag to give to go build so it does a cd into the directory before running?

No. (The argument to go build is, strictly speaking, a package path, not a directory.)

[gopherbot]

Timed out in state WaitingForInfo. Closing.

(I am just a bot, though. Please speak up if this is a mistake or you have the requested information.)