x/tools/gopls: "could not import ___" after adding new _test package

[zikaeroh]

Please answer these questions before submitting your issue. Thanks!

What did you do?

I created a package, added code to it, then added a _test package to the same directory.

What did you expect to see?

No errors, I can start working on that package.

What did you see instead?

On finishing typing my package name, all of the imports in my non-test code had "could not import" errors.

Logs: https://gist.github.com/zikaeroh/6ba035d30a5493e19e8673b47ace4f7c

Build info

golang.org/x/tools/gopls master
    golang.org/x/tools/gopls@v0.1.8-0.20200117220505-0cba7a3a9ee9 h1:nzvuLbmeJ+AcY2QpRizKDzip5dbZHStOlteBZR29PH8=
    github.com/BurntSushi/toml@v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
    github.com/sergi/go-diff@v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
    golang.org/x/mod@v0.1.1-0.20191105210325-c90efee705ee h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
    golang.org/x/sync@v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
    golang.org/x/tools@v0.0.0-20200117220505-0cba7a3a9ee9 h1:KOkk4e2xd5OeCDJGwacvr75ICCbCsShrHiqPEdsA9hg=
    golang.org/x/xerrors@v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
    honnef.co/go/tools@v0.0.1-2019.2.3 h1:3JgtbtFHMiCmsznwGVTUWbgGov+pVqnlf1dEJTNAXeM=
    mvdan.cc/xurls/v2@v2.1.0 h1:KaMb5GLhlcSX+e+qhbRJODnUUBvlw01jt4yrjFIHAuA=

Go info

go version go1.13.6 linux/amd64

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/jake/.cache/go-build"
GOENV="/home/jake/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/jake/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/jake/zikaeroh/hortbot/hortbot/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-build755509892=/tmp/go-build -gno-record-gcc-switches"

[gopherbot]

Change https://golang.org/cl/215743 mentions this issue: go/packages: handle an overlay edge case with test variants

[stamblerre]

This sounds exactly like #35949, so we will have to be careful to not make the same mistakes here. Go 1.14 will have the fix for #35973, which should help things a little.

[stamblerre]

This issue is a combination of #35973 and #36661. With Go 1.14, the imports no longer disappear, since that fix is available there. The fact that we don't recover from the imports disappearing can be attributed to this fact (#36661 (comment)):

The problem here is that the initial workspace load finds nothing, and AFAIK we currently have no mechanism for adding packages to the workspace set, so they don't ever end up getting diagnosed in the background.

I will then close this issue and continue work on modifying the workspace packages set on #36661.

[stamblerre]

On the further investigation, the issue persists apart from what #36661 covers. I will keep investigating, but as it already existed in gopls/v0.2.2, I will move it out of the gopls/v0.3.0 milestone.