cmd/go: go clean -testcache fails if GOCACHE directory does not exist #29100
Description
What version of Go are you using (go version)?
$ go version go version go1.11.2 darwin/amd64
Does this issue reproduce with the latest release?
Yes. It may be affected by #26794 for 1.12, but looking at the code, I think the bug is still there.
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GOARCH="amd64" GOBIN="/Users/mxk/bin" GOCACHE="/Users/mxk/Library/Caches/go-build" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/mxk/.go" GOPROXY="" GORACE="" GOROOT="/usr/local/Cellar/go/1.11.2/libexec" GOTMPDIR="" GOTOOLDIR="/usr/local/Cellar/go/1.11.2/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" 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/xg/rnkm_hgs5298dsx212f1_y2c0000gp/T/go-build752263492=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
cachedir=$(go env GOCACHE)
mv $cachedir $cachedir.old
go clean -testcache
mv $cachedir.old $cachedirWhat did you expect to see?
No errors and an exit code of 0.
What did you see instead?
go clean -testcache: open /Users/mxk/Library/Caches/go-build/testexpire.txt: no such file or directory
exit code 1
The -testcache flag assumes that the cache directory exists. When that's not the case, there is nothing to clear, so the command should exit normally.