proxy.golang.org: "410 Gone" on tag publicly available for 50 days

[MMulthaupt]

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

go1.13 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

GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/martin/.cache/go-build"
GOENV="/home/martin/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/martin/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/martin/gitlab/godown-builder/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-build504237898=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Write a go.mod with one of these entries:
require github.com/shirou/gopsutil v2.19.8+incompatible (Released Sep 1)
require github.com/shirou/gopsutil v2.19.7+incompatible (Released Jul 31)

What did you expect to see?

go: finding github.com/shirou/gopsutil v2.19.8+incompatible

What did you see instead?

verifying github.com/shirou/gopsutil@v2.19.8+incompatible/go.mod: github.com/shirou/gopsutil@v2.19.8+incompatible/go.mod: reading https://sum.golang.org/lookup/github.com/shirou/gopsutil@v2.19.8+incompatible: 410 Gone

Additional Information

v2.19.6 does work, and has no changes to the project's structure (i.e., still has no v2 subdirectory):
require github.com/shirou/gopsutil v2.19.6+incompatible (Released Jun 27)

[heschi]

From https://sum.golang.org/lookup/github.com/shirou/gopsutil@v2.19.8+incompatible: not found: github.com/shirou/gopsutil@v2.19.8+incompatible: invalid version: +incompatible suffix not allowed: module contains a go.mod file, so semantic import versioning is required.

This is new validation in 1.13; see "Version validation" in https://golang.org/doc/go1.13 for details. v2.19.6+incompatible is present because it was added before sum.golang.org was upgraded to 1.13.

Closing, since everything here is working correctly. gopsutil will need to add the necessary /v2 suffix to its go.mod and use non-+incompatible versions, or remove its go.mod entirely.