GO111MODULE=on go get -v github.com/google/ko/cmd/ko failed

[dove-young]

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

$ go version
go version go1.13.6 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="/root/.cache/go-build"
GOENV="/root/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/root/go"
GOPRIVATE=""
GOPROXY="direct"
GOROOT="/usr/lib/golang"
GOSUMDB="off"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/golang/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build704158439=/tmp/go-build -gno-record-gcc-switches"
```

What did you do?

GO111MODULE=on go get -v  github.com/google/ko/cmd/ko
go: finding github.com/google/ko/cmd/ko latest
go: finding github.com/google/ko/cmd latest
get "modernc.org/strutil": found meta tag get.metaImport{Prefix:"modernc.org/strutil", VCS:"git", RepoRoot:"https://gitlab.com/cznic/strutil"} at //modernc.org/strutil?go-get=1
get "modernc.org/golex": found meta tag get.metaImport{Prefix:"modernc.org/golex", VCS:"git", RepoRoot:"https://gitlab.com/cznic/golex"} at //modernc.org/golex?go-get=1
get "modernc.org/mathutil": found meta tag get.metaImport{Prefix:"modernc.org/mathutil", VCS:"git", RepoRoot:"https://gitlab.com/cznic/mathutil"} at //modernc.org/mathutil?go-get=1
get "modernc.org/cc": found meta tag get.metaImport{Prefix:"modernc.org/cc", VCS:"git", RepoRoot:"https://gitlab.com/cznic/cc"} at //modernc.org/cc?go-get=1
get "modernc.org/xc": found meta tag get.metaImport{Prefix:"modernc.org/xc", VCS:"git", RepoRoot:"https://gitlab.com/cznic/xc"} at //modernc.org/xc?go-get=1
go get: github.com/google/ko@v0.5.1 requires
        github.com/google/go-containerregistry@v0.0.0-20200310013544-4fe717a9b4cb requires
        k8s.io/code-generator@v0.17.2 requires
        gonum.org/v1/netlib@v0.0.0-20190331212654-76723241ea4e requires
        modernc.org/cc@v1.0.0: reading modernc.org/cc/go.mod at revision v1.0.0: git fetch -f https://gitlab.com/cznic/cc refs/heads/*:refs/heads/* refs/tags/*:refs/tags/* in /root/go/pkg/mod/cache/vcs/214c7c8b018f9220f253771b1476659b6c905c4196c32b80b07a212616372040: exit status 128:
        error: RPC failed; result=22, HTTP code = 404
        fatal: The remote end hung up unexpectedly

What did you expect to see?

What did you see instead?