cmd/go: downloaded module missing a source file

[clarkezone]

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

go version go1.12 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

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/jamesclarke/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/jamesclarke/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/jamesclarke/Source/Temp/gotest/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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/6m/dh9gmlhd00g9qkdsv86pj2dw0000gn/T/go-build486175678=/tmp/go-build -gno-record-gcc-switches -fno-common" 

What did you do?

1. Create a new project
2. go mod init gitHub.com/foo/bar
3. create a hello.go file containing:

package main

import (
        "golang.org/x/crypto/ssh/terminal"
)

func main() {
        _, err := terminal.MakeRaw(0)
        if err != nil {
                log.Fatal(err)
        }
}

4. go build

What did you expect to see?

Program compiles

What did you see instead?

go build
# golang.org/x/sys/unix
../../../go/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12/unix/fcntl_darwin.go:15:42: undefined: Flock_t              
../../../go/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12/unix/ioctl.go:14:47: undefined: Winsize                     
../../../go/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12/unix/ioctl.go:25:47: undefined: Termios                     
../../../go/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12/unix/sockcmsg_unix.go:50:18: undefined: Cmsghdr             
../../../go/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12/unix/sockcmsg_unix.go:56:9: undefined: Cmsghdr  

Tried go get golang.org/x/sys and build still fails

[bcmills]

(CC @jayconrod)

All of the missing declarations from that error message come from ztypes_darwin_amd64.go, so it sounds like that file is somehow missing from the extracted module.

Were you by any chance using this version of golang.org/x/sys with a previous version of the Go toolchain, particularly with concurrent invocations of go commands?

If not, please save your main module's go.mod and go.sum files, and save (preferably to a tar or zip archive) the contents of the $GOPATH/pkg/mod/cache/download/golang.org/x/sys/@v and $GOPATH/pkg/mod/golang.org/x/sys@v0.0.0-20190225065934-cc5685c2db12 directory trees (for later investigation), and run go clean -modcache to see if a fresh copy of the module is corrupted in the same way.

[bcmills]

I would be especially interested to know:
a. Are the missing files present in the .zip file for that version of the module?
b. Are there any other files present in the .zip file but missing from the unzipped copy of the module?

[clarkezone]

I have had previous version's of Go installed but no concurrent invocations of go cmd. The go clean -modcache did fix it, I have the archive if you are interested

[bcmills]

Yes, please do attach the archive. (It probably won't have any new clues, but you never know...)

[clarkezone]

Here you go

Archive.zip