On Linux & MacOS we can write this; on Windows it fails with a "sharing violation":

path := "delete-after-open"
fd, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0600)
if err != nil { ... }
err = os.Remove(path)            // or os.Rename(path, path+"2")
if err != nil { ... }
fd.Close()

If you develop on Windows and deploy to Linux etc, and your code relies on this undocumented GOOS=windows behavior of os.Rename() & .Remove(), it is broken and perhaps vulnerable. Note that package "os" has fifteen mentions of other Windows-specific behavior.

To fix this, syscall.Open() at https://golang.org/src/syscall/syscall_windows.go#L272
needs sharemode |= FILE_SHARE_DELETE

Microsoft recommends this be made the default: #32088 (comment)
Rust made it a default: https://doc.rust-lang.org/std/os/windows/fs/trait.OpenOptionsExt.html
Mingw-w64 made it a default seven years ago:
https://sourceforge.net/p/mingw-w64/code/HEAD/tree/stable/v3.x/mingw-w64-headers/include/ntdef.h#l858
Erlang made it a default over six years ago: erlang/otp@0e02f48
Python couldn't adopt it due to limitations of MSVC runtime: https://bugs.python.org/issue15244

Therefore syscall.Open() should use file_share_delete by default, and syscall should provide both:
a) a global switch to disable it (for any existing apps that rely on its absence), and
b) a flag for use with os.OpenFile() to disable it on a specific file handle.

Update after #32088 (comment) by @rsc:
a) os.Create/Open/OpenFile() should always enable file_share_delete on Windows,
b) syscall.Open() on Windows should accept a flag which enables file_share_delete, and
c) syscall on Windows should export a constant for the new flag.

The docs for os.Remove() should also note that to reuse a filename after deleting an open file on Windows, one must do: os.Rename(path, unique_path); os.Remove(unique_path).

Win API docs
https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-deletefilea
https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea

If there is a reason not to do this, it should be documented in os.Remove() & .Rename().

cc @alexbrainman
@gopherbot add OS-Windows