os: Testing re. hardlinks failing on macs.

[zanerock]

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

go version go1.11.5 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="/Users/zane/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/zane/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=""
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/x7/dkrqh9dd6yd4kx0xs6st40980000gn/T/go-build149262009=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

1. Get on a mac.
2. Create a package that imports the standard os package.
3. Run: go test all

I am attempting to run go test all as prior to publishing packages (as recommended here: https://github.com/golang/go/wiki/Modules). However, the test fails with:

What did you expect to see?

Standard library tests should pass.

What did you see instead?

--- FAIL: TestStatError (0.00s)
    os_test.go:200: symlink no-such-file symlink: permission denied
--- FAIL: TestHardLink (0.00s)
    os_test.go:694: open "hardlinktestto" failed: open hardlinktestto: permission denied
--- FAIL: TestSymlink (0.00s)
    os_test.go:780: Create("symlinktestto") failed: open symlinktestto: permission denied
--- FAIL: TestLongSymlink (0.00s)
    os_test.go:847: symlink "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef", "longsymlinktestfrom" failed: symlink 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef longsymlinktestfrom: permission denied
--- FAIL: TestRename (0.00s)
    os_test.go:868: open "renamefrom" failed: open renamefrom: permission denied
--- FAIL: TestRenameOverwriteDest (0.00s)
    os_test.go:896: write file "renameto" failed: open renameto: permission denied
--- FAIL: TestAppend (0.00s)
    os_test.go:1684: Open: open append.txt: permission denied
--- FAIL: TestSameFile (0.00s)
    os_test.go:1766: Create(a): open a: permission denied
FAIL
FAIL	os	19.145s

[ianlancetaylor]

This is failing because you have a read-only source directory. This is fixed on tip and in 1.12. See also #28387.