I had previously bemoaned the inability to figure out why my automounts were being so stupid in Catalina and after periodically searching and giving up I finally found a bread crumb that showed me the way.
Previously I automounted several shares in a directory under my home directory
Shares, but ran into a situation where it duplicated the mounts
frequently and often crashed while accessing data in a NFS mounted directory.
It looks like this is no longer the way... exactly.
The New Way
It looks like what Apple wants you to do in the brave new world is to create an entry in / using their virtual symbolic link facility (synthetic.conf(5)) and mount under that. A quick look at the manpage and I was able to come up with the following:
# Create a virtual /Shares folder to automount into Shares
Then I just changed my
auto_master to mount my
auto_nfs map on
It looks like the automounter in macOS will resolve that synthetic location
/System/Volumes/Data/Shares, so I symlinked that into my homedir using
good old ln(1). After a quick
automount -vc my mounts appeared and
after a several minutes I've noticed no duplication (previously I'd have 20
or 30 duplicates by now).
I wish this was better documented but hopefully this will help someone else!