cmd/go: clean -cache -n should not delete cache

[jquirke]

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

$ go version
go version go1.14.3 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
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/qjeremy/Library/Caches/go-build"
GOENV="/Users/qjeremy/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/qjeremy/gocode"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.14.3/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.14.3/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
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/z7/k_sywh750_93syv7f394mq8c0000gn/T/go-build676007682=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

1. See that there are cache artifacts from prior builds.

qjeremy-C02TX0NYHTDG:wayfare qjeremy$ ls -l `go env GOCACHE` | head -10
total 24
drwxr-xr-x  3 qjeremy  staff   96 May 25 22:11 00
drwxr-xr-x  3 qjeremy  staff   96 May 25 22:11 01
drwxr-xr-x  4 qjeremy  staff  128 May 25 22:11 02
drwxr-xr-x  2 qjeremy  staff   64 May 25 22:11 03
drwxr-xr-x  2 qjeremy  staff   64 May 25 22:11 04
drwxr-xr-x  3 qjeremy  staff   96 May 25 22:11 05
drwxr-xr-x  5 qjeremy  staff  160 May 25 22:11 06
drwxr-xr-x  5 qjeremy  staff  160 May 25 22:11 07
drwxr-xr-x  4 qjeremy  staff  128 May 25 22:11 08

2. Attempt to clean the cache using go clean -cache but with the -n flag, which according to documentation, states that it only prints the commands it would run, not run them.

$go clean -cache -n Output

rm -r /Users/qjeremy/Library/Caches/go-build/00 /Users/qjeremy/Library/Caches/go-build/01 /Users/qjeremy/Library/Caches/go-build/02 /Users/qjeremy/Library/Caches/go-build/03 /Users/qjeremy/Library/Caches/go-build/04 /Users/qjeremy/Library/Caches/go-build/05 /Users/qjeremy/Library/Caches/go-build/06 /Users/qjeremy/Library/Caches/go-build/07 /Users/qjeremy/Library/Caches/go-build/08 /Users/qjeremy/Library/Caches/go-build/09 /Users/qjeremy/Library/Caches/go-build/0a /Users/qjeremy/Library/Caches/go-build/0b /Users/qjeremy/Library/Caches/go-build/0c /Users/qjeremy/Library/Caches/go-build/0d /Users/qjeremy/Library/Caches/go-build/0e /Users/qjeremy/Library/Caches/go-build/0f /Users/qjeremy/Library/Caches/go-build/10 /Users/qjeremy/Library/Caches/go-build/11 /Users/qjeremy/Library/Caches/go-build/12 /Users/qjeremy/Library/Caches/go-build/13 /Users/qjeremy/Library/Caches/go-build/14 /Users/qjeremy/Library/Caches/go-build/15 /Users/qjeremy/Library/Caches/go-build/16 /Users/qjeremy/Library/Caches/go-build/17 /Users/qjeremy/Library/Caches/go-build/18 /Users/qjeremy/Library/Caches/go-build/19 /Users/qjeremy/Library/Caches/go-build/1a /Users/qjeremy/Library/Caches/go-build/1b /Users/qjeremy/Library/Caches/go-build/1c /Users/qjeremy/Library/Caches/go-build/1d /Users/qjeremy/Library/Caches/go-build/1e /Users/qjeremy/Library/Caches/go-build/1f /Users/qjeremy/Library/Caches/go-build/20 /Users/qjeremy/Library/Caches/go-build/21 /Users/qjeremy/Library/Caches/go-build/22 /Users/qjeremy/Library/Caches/go-build/23 /Users/qjeremy/Library/Caches/go-build/24 /Users/qjeremy/Library/Caches/go-build/25 /Users/qjeremy/Library/Caches/go-build/26 /Users/qjeremy/Library/Caches/go-build/27 /Users/qjeremy/Library/Caches/go-build/28 /Users/qjeremy/Library/Caches/go-build/29 /Users/qjeremy/Library/Caches/go-build/2a /Users/qjeremy/Library/Caches/go-build/2b /Users/qjeremy/Library/Caches/go-build/2c /Users/qjeremy/Library/Caches/go-build/2d 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/Users/qjeremy/Library/Caches/go-build/5c /Users/qjeremy/Library/Caches/go-build/5d /Users/qjeremy/Library/Caches/go-build/5e /Users/qjeremy/Library/Caches/go-build/5f /Users/qjeremy/Library/Caches/go-build/60 /Users/qjeremy/Library/Caches/go-build/61 /Users/qjeremy/Library/Caches/go-build/62 /Users/qjeremy/Library/Caches/go-build/63 /Users/qjeremy/Library/Caches/go-build/64 /Users/qjeremy/Library/Caches/go-build/65 /Users/qjeremy/Library/Caches/go-build/66 /Users/qjeremy/Library/Caches/go-build/67 /Users/qjeremy/Library/Caches/go-build/68 /Users/qjeremy/Library/Caches/go-build/69 /Users/qjeremy/Library/Caches/go-build/6a /Users/qjeremy/Library/Caches/go-build/6b /Users/qjeremy/Library/Caches/go-build/6c /Users/qjeremy/Library/Caches/go-build/6d /Users/qjeremy/Library/Caches/go-build/6e /Users/qjeremy/Library/Caches/go-build/6f /Users/qjeremy/Library/Caches/go-build/70 /Users/qjeremy/Library/Caches/go-build/71 /Users/qjeremy/Library/Caches/go-build/72 /Users/qjeremy/Library/Caches/go-build/73 /Users/qjeremy/Library/Caches/go-build/74 /Users/qjeremy/Library/Caches/go-build/75 /Users/qjeremy/Library/Caches/go-build/76 /Users/qjeremy/Library/Caches/go-build/77 /Users/qjeremy/Library/Caches/go-build/78 /Users/qjeremy/Library/Caches/go-build/79 /Users/qjeremy/Library/Caches/go-build/7a /Users/qjeremy/Library/Caches/go-build/7b /Users/qjeremy/Library/Caches/go-build/7c /Users/qjeremy/Library/Caches/go-build/7d /Users/qjeremy/Library/Caches/go-build/7e /Users/qjeremy/Library/Caches/go-build/7f /Users/qjeremy/Library/Caches/go-build/80 /Users/qjeremy/Library/Caches/go-build/81 /Users/qjeremy/Library/Caches/go-build/82 /Users/qjeremy/Library/Caches/go-build/83 /Users/qjeremy/Library/Caches/go-build/84 /Users/qjeremy/Library/Caches/go-build/85 /Users/qjeremy/Library/Caches/go-build/86 /Users/qjeremy/Library/Caches/go-build/87 /Users/qjeremy/Library/Caches/go-build/88 /Users/qjeremy/Library/Caches/go-build/89 /Users/qjeremy/Library/Caches/go-build/8a /Users/qjeremy/Library/Caches/go-build/8b /Users/qjeremy/Library/Caches/go-build/8c /Users/qjeremy/Library/Caches/go-build/8d /Users/qjeremy/Library/Caches/go-build/8e /Users/qjeremy/Library/Caches/go-build/8f /Users/qjeremy/Library/Caches/go-build/90 /Users/qjeremy/Library/Caches/go-build/91 /Users/qjeremy/Library/Caches/go-build/92 /Users/qjeremy/Library/Caches/go-build/93 /Users/qjeremy/Library/Caches/go-build/94 /Users/qjeremy/Library/Caches/go-build/95 /Users/qjeremy/Library/Caches/go-build/96 /Users/qjeremy/Library/Caches/go-build/97 /Users/qjeremy/Library/Caches/go-build/98 /Users/qjeremy/Library/Caches/go-build/99 /Users/qjeremy/Library/Caches/go-build/9a /Users/qjeremy/Library/Caches/go-build/9b /Users/qjeremy/Library/Caches/go-build/9c /Users/qjeremy/Library/Caches/go-build/9d /Users/qjeremy/Library/Caches/go-build/9e /Users/qjeremy/Library/Caches/go-build/9f /Users/qjeremy/Library/Caches/go-build/a0 /Users/qjeremy/Library/Caches/go-build/a1 /Users/qjeremy/Library/Caches/go-build/a2 /Users/qjeremy/Library/Caches/go-build/a3 /Users/qjeremy/Library/Caches/go-build/a4 /Users/qjeremy/Library/Caches/go-build/a5 /Users/qjeremy/Library/Caches/go-build/a6 /Users/qjeremy/Library/Caches/go-build/a7 /Users/qjeremy/Library/Caches/go-build/a8 /Users/qjeremy/Library/Caches/go-build/a9 /Users/qjeremy/Library/Caches/go-build/aa /Users/qjeremy/Library/Caches/go-build/ab /Users/qjeremy/Library/Caches/go-build/ac /Users/qjeremy/Library/Caches/go-build/ad /Users/qjeremy/Library/Caches/go-build/ae /Users/qjeremy/Library/Caches/go-build/af /Users/qjeremy/Library/Caches/go-build/b0 /Users/qjeremy/Library/Caches/go-build/b1 /Users/qjeremy/Library/Caches/go-build/b2 /Users/qjeremy/Library/Caches/go-build/b3 /Users/qjeremy/Library/Caches/go-build/b4 /Users/qjeremy/Library/Caches/go-build/b5 /Users/qjeremy/Library/Caches/go-build/b6 /Users/qjeremy/Library/Caches/go-build/b7 /Users/qjeremy/Library/Caches/go-build/b8 /Users/qjeremy/Library/Caches/go-build/b9 /Users/qjeremy/Library/Caches/go-build/ba /Users/qjeremy/Library/Caches/go-build/bb /Users/qjeremy/Library/Caches/go-build/bc /Users/qjeremy/Library/Caches/go-build/bd /Users/qjeremy/Library/Caches/go-build/be /Users/qjeremy/Library/Caches/go-build/bf /Users/qjeremy/Library/Caches/go-build/c0 /Users/qjeremy/Library/Caches/go-build/c1 /Users/qjeremy/Library/Caches/go-build/c2 /Users/qjeremy/Library/Caches/go-build/c3 /Users/qjeremy/Library/Caches/go-build/c4 /Users/qjeremy/Library/Caches/go-build/c5 /Users/qjeremy/Library/Caches/go-build/c6 /Users/qjeremy/Library/Caches/go-build/c7 /Users/qjeremy/Library/Caches/go-build/c8 /Users/qjeremy/Library/Caches/go-build/c9 /Users/qjeremy/Library/Caches/go-build/ca /Users/qjeremy/Library/Caches/go-build/cb /Users/qjeremy/Library/Caches/go-build/cc /Users/qjeremy/Library/Caches/go-build/cd /Users/qjeremy/Library/Caches/go-build/ce /Users/qjeremy/Library/Caches/go-build/cf /Users/qjeremy/Library/Caches/go-build/d0 /Users/qjeremy/Library/Caches/go-build/d1 /Users/qjeremy/Library/Caches/go-build/d2 /Users/qjeremy/Library/Caches/go-build/d3 /Users/qjeremy/Library/Caches/go-build/d4 /Users/qjeremy/Library/Caches/go-build/d5 /Users/qjeremy/Library/Caches/go-build/d6 /Users/qjeremy/Library/Caches/go-build/d7 /Users/qjeremy/Library/Caches/go-build/d8 /Users/qjeremy/Library/Caches/go-build/d9 /Users/qjeremy/Library/Caches/go-build/da /Users/qjeremy/Library/Caches/go-build/db /Users/qjeremy/Library/Caches/go-build/dc /Users/qjeremy/Library/Caches/go-build/dd /Users/qjeremy/Library/Caches/go-build/de /Users/qjeremy/Library/Caches/go-build/df /Users/qjeremy/Library/Caches/go-build/e0 /Users/qjeremy/Library/Caches/go-build/e1 /Users/qjeremy/Library/Caches/go-build/e2 /Users/qjeremy/Library/Caches/go-build/e3 /Users/qjeremy/Library/Caches/go-build/e4 /Users/qjeremy/Library/Caches/go-build/e5 /Users/qjeremy/Library/Caches/go-build/e6 /Users/qjeremy/Library/Caches/go-build/e7 /Users/qjeremy/Library/Caches/go-build/e8 /Users/qjeremy/Library/Caches/go-build/e9 /Users/qjeremy/Library/Caches/go-build/ea /Users/qjeremy/Library/Caches/go-build/eb /Users/qjeremy/Library/Caches/go-build/ec /Users/qjeremy/Library/Caches/go-build/ed /Users/qjeremy/Library/Caches/go-build/ee /Users/qjeremy/Library/Caches/go-build/ef /Users/qjeremy/Library/Caches/go-build/f0 /Users/qjeremy/Library/Caches/go-build/f1 /Users/qjeremy/Library/Caches/go-build/f2 /Users/qjeremy/Library/Caches/go-build/f3 /Users/qjeremy/Library/Caches/go-build/f4 /Users/qjeremy/Library/Caches/go-build/f5 /Users/qjeremy/Library/Caches/go-build/f6 /Users/qjeremy/Library/Caches/go-build/f7 /Users/qjeremy/Library/Caches/go-build/f8 /Users/qjeremy/Library/Caches/go-build/f9 /Users/qjeremy/Library/Caches/go-build/fa /Users/qjeremy/Library/Caches/go-build/fb /Users/qjeremy/Library/Caches/go-build/fc /Users/qjeremy/Library/Caches/go-build/fd /Users/qjeremy/Library/Caches/go-build/fe /Users/qjeremy/Library/Caches/go-build/ff

3. Verify the cache is NOT removed

What did you expect to see?

The cache should not be removed, but a series of rm command should be printed.

What did you see instead?

The cache was removed, (but the series of rm commands was printed).

Either the documentation is ambiguous (should it apply to clean -cache as well as packages?) or this is a bug.

$ls -l `go env GOCACHE` | head -10
qjeremy-C02TX0NYHTDG:wayfare qjeremy$ ls -l `go env GOCACHE` | head -10
total 24
-rw-r--r--  1 qjeremy  staff  170 Apr 12  2018 README
-rw-r--r--  1 qjeremy  staff   20 May 25 22:01 testexpire.txt
-rw-r--r--  1 qjeremy  staff   10 May 25 21:29 trim.txt

[mvdan]

CC @jayconrod @matloob @bcmills

[tpaschalis]

I can attest to the fact! I just tried with go1.14.3 and the cache was indeed deleted.

From what I see the -n flag in clean.go is defined as part of the buildN build flag.

The flag is populated correctly, but in the if cleanCache block, we do print the commands, but it looks like we're missing a if cfg.BuildN { continue} or a if !cfg.BuildN block like it exists in the clean function.

If it's okay with you, I'll try to open a CL and get this fixed, as well as see if any tests exist to avoid this in the future.

[mvdan]

@tpaschalis by all means, send a CL. go clean should have test scripts under src/cmd/go/testdata/script.

[gopherbot]

Change https://golang.org/cl/235140 mentions this issue: cmd/go: clean -cache -n should not delete cache