cmd/go: error if GOCACHE is set but is not an absolute path

[mileusna]

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

$ 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

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="on"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/mileusna/Dropbox/"
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=""
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/3r/3lsskhdx6db_lw1m06qfr62c0000gn/T/go-build512222336=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

# go test

What did you expect to see?

Test running

What did you see instead?

Build error and test failed probably due to new structure for cache directories in 1.12

# devgit.ha.rs/mi2/cmd/mnsinfo-api.test
/var/folders/3r/3lsskhdx6db_lw1m06qfr62c0000gn/T/go-build218744920/b001/_testmain.go:10:2: can't open import: "devgit.ha.rs/mi2/cmd/mnsinfo-api": open on/f9/f95617d4d2ff6b243c4e9e04cf4904cdde38953c391e5a9abb6291e18732b096-d: no such file or directory
FAIL	devgit.ha.rs/mi2/cmd/mnsinfo-api [build failed]
Error: Tests failed.

Executing go clean -cache will fix a problem for a while, but then it starts occurring again.

[ianlancetaylor]

Don't set GOCACHE=on. GOCACHE should be the path to the cache directory you want to use. We should probably give an error if GOCACHE is set and it is not an absolute path.

[mileusna]

Thanks, I was wondering why the hell the tmp directory is named "on". 😂

I have an explanation for this. The story goes that I had this settings on "off", but 1.12 didn't want to compile with GOCACHE="off". I try to delete it from .bash_profile but VSCode haven't picked up that change after several VSCode restarts, so I put it back and set it to "on". Compile started to work and I end up with "on/" directory for cache files 😂 but go test started to fail.

[agnivade]

Also see previous conversation here #28290.

[gopherbot]

Change https://golang.org/cl/164200 mentions this issue: cmd/go/internal/cache: disable builds if GOCACHE is not an absolute path

[mileusna]

Now when I know for this issue, I don't mind if it will be relative or absolute path. The off value is history now, so I guess I will never use this env var ever again.

But for transition period like now when I upgraded from 1.11 to 1.12 and moved from "off" to "on" 😆 warning on abs path would save me a lot of wasted time. :)

[mileusna]

Does anyone know how can I avoid cache in go test now when there is no GOCACHE=off?

--- PASS: TestObjDef (0.02s)
PASS
ok  	devgit.ha.rs/mi2/cmd/mnsinfo-api	(cached)
Success: Tests passed.

[agnivade]

https://golang.org/cmd/go/#hdr-Test_packages

The idiomatic way to disable test caching explicitly is to use -count=1.

[oiooj]

@gopherbot please backport to 1.12

[gopherbot]

Backport issue(s) opened: #30493 (for 1.12).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.