Thank you for the additional information, @fscheidt …
I can attest that using mklink /J to create a “directory junction” (the directory version of what’s called a “hard link” on Windows) has been working fine for me for months, at least since December, when I posted about it, above, on Windows 10.
And thank you for the suggestion re creating the link in a different work directory tree, outside the vaults base dir … but still no dice.
Nothing happens upon attempting to open the symlink to the current vault, while current vault is open. (Must be something different in how Obsidian or one of the underlying frameworks handles things in Mac vs. Linux?)
(My vault is in ~/Dropbox/haribol_vault, I put link in ~/test/haribol_vault_link). On MacOS 10.14.3 Mojave, FWIW.
What I just tried, and seems to be working for now, as mentioned by others above, is nesting my vault in an empty “container” folder, like so:
/~
|-- vault_container
|-- vault
May be some caveats or further settings tweaks required, messing with the .obsidian directory (whether to have separate .obsidian cache/settings for each, or try to share the same), but seems to work for now.
And yes, as I remember, the order of arguments (for target & destination) in Windows mklink is opposite of unix ln … confusing. Always doublecheck first!