Daniel Martí ef06a5f44a misc/reboot: don't use symlinks when copying GOROOT/src ... go:embed disallows using symlinked files by design. crypto/elliptic is the first std package to use it as of CL 380475, and unfortunately that broke the TestRepeatBootstrap long test. The reason it uses symlinks is for speed; it wants to copy GOROOT/src, but regular files aren't going to be modified in any way, so a symlink, if supported, means not needing to copy the contents. Replace the symlink attempt with hard links, which will mean regular files remain as such, fixing go:embed. It's worth noting that on many systems hard links won't work, as the temporary filesystem tends to be separate, but it doesn't hurt to try. In my system, where /tmp is tmpfs, the test now copies more bytes. With the added Logf, I can see overlayDir goes from ~30ms to ~100ms. This makes sense, as GOROOT/src currently weighs around 100MiB. To alleviate that slow-down, stop copying testdata directories, as they currently weigh around 20MiB and aren't needed for the test. This gets overlayDir on my system down to an acceptable ~70ms. I briefly considered teaching overlayDir what files can be symlinks, but that seemed fairly complex long-term, as any file could be embedded. While here, start using testing.T.TempDir and fs.WalkDir. For #50995. Change-Id: I17947e6bdee96237e1ca0606ad0b95e7c5987bc1 Reviewed-on: https://go-review.googlesource.com/c/go/+/383995 Trust: Daniel Martí <mvdan@mvdan.cc> Trust: Bryan Mills <bcmills@google.com> Run-TryBot: Bryan Mills <bcmills@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>		2022-02-08 15:30:12 +00:00
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experiment_toolid_test.go
overlaydir_test.go	misc/reboot: don't use symlinks when copying GOROOT/src	2022-02-08 15:30:12 +00:00
reboot_test.go	misc/reboot: don't use symlinks when copying GOROOT/src	2022-02-08 15:30:12 +00:00