go/build: tests use a non-hermetic "go" binary

[bcmills]

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

$ go version
go version devel +567fe4650b Thu May 21 13:43:48 2020 -0400 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="/usr/local/google/home/bcmills/.cache/go-build"
GOENV="/usr/local/google/home/bcmills/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/usr/local/google/home/bcmills/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/usr/local/google/home/bcmills"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/google/home/bcmills/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/google/home/bcmills/go/pkg/tool/linux_amd64"
GCCGO="/usr/local/google/home/bcmills/bin/gccgo"
GOAMD64="alignedjumps"
AR="ar"
CC="gcc"
CXX="c++"
CGO_ENABLED="1"
GOMOD="/usr/local/google/home/bcmills/go/src/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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build456911771=/tmp/go-build -gno-record-gcc-switches"

What did you do?

~/go/src$ ls ~/minbin
ar  as  cat  clang  diff  echo  env  gcc  ld  pwd  uname  whoami

~/go/src$ PATH=~/minbin ../bin/go test go/build
--- FAIL: TestImportDirNotExist (0.00s)
    --- FAIL: TestImportDirNotExist/GO111MODULE=on (0.00s)
        build_test.go:356: Import(full, 0) got error: "go/build: go list go/build/doesnotexist: exec: \"go\": executable file not found in $PATH\n\n", want "cannot find package" or "is not in GOROOT" error
        build_test.go:356: Import(full, FindOnly) got error: "go/build: go list go/build/doesnotexist: exec: \"go\": executable file not found in $PATH\n\n", want "cannot find package" or "is not in GOROOT" error
--- FAIL: TestImportPackageOutsideModule (0.00s)
    build_test.go:480: error when importing package when no go.mod is present: got "go/build: go list example.com/p: exec: \"go\": executable file not found in $PATH\n\n"; want "cannot find module providing package"
FAIL
FAIL    go/build        0.107s
FAIL

What did you expect to see?

Tests run using the go command from the same GOROOT used to build the go/build test.

What did you see instead?

A test failure due to the go command not being present in PATH.

[gopherbot]

Change https://golang.org/cl/234880 mentions this issue: all: use a hermetic "go" tool in standard-library tests