On Jul 22 14:53, Jon Turney wrote: > On 21/07/2021 09:19, Corinna Vinschen wrote: > > On Jul 19 17:31, Jon Turney wrote: > > > I'm not sure this is the best idea, since it adds more configurations that > > > aren't going to get tested often, but the idea is that this would enable > > > proper and consistent control of the symlink type used from setup, as > > > discussed in [1]. > > > > > > [1] https://cygwin.com/pipermail/cygwin-apps/2021-May/041327.html > > > > Why isn't it sufficient to use 'winsymlinks:native' from setup? > > I think in the default Windows configuration (developer mode off, no > SeCreateSymbolicLinkPrivilege), 'native' will try to create a native symlink > and fail, and fallback to WSL IO_REPARSE_TAG_LX_SYMLINK reparse point, then > magic cookie + sys attribute. > > This leads to cygwin installations with WSL symlinks created by post-install > scripts, which can't be put into Docker containers [1], which is the > original problem I was trying to fix. > > [1] https://cygwin.com/pipermail/cygwin/2020-August/245994.html
Did nobody ask the Docker guys why they fail to support perfectly valid reparse points? > I haven't yet looked at adding 'native' symlink support to setup itself, but > it's probably going to be a bit of a pain. That may be not a bad idea after all. Setup typically runs as elevated process, so it has the required permissions to create native symlinks. Scripts could then run with CYGWIN=winsymlinks:native by default. As long as nobody has the hare-brained idea to move a Cygwin distro manually, native symlinks should be just as well as Cygwin symlinks. > > The way we express symlinks shouldn't be a user choice, really. The > > winsymlinks thingy was only ever introduced in a desperate attempt to > > improve access to symlinks from native tools, and I still don't see a > > way around that. But either way, what's the advantage in allowing the > > user complete control over the type, even if the type is only useful in > > Cygwin? > If we can come up with a fixed policy that works everywhere, there is no > advantage. But that seems unlikely :) > > I could buy an argument that 'native' should be the default (although maybe > all that does is slow things down in the majority of installs?). It may slow down installations a tiny little bit because the target paths have to be converted to POSIX, but I doubt this is more than just a marginal slowdown. Corinna
