cmd/cacheserver: keeps trying, and failing, Watch("nf@wh3rd.net/")

[dominikh]

I have a cacheserver instance running locally. I've added cache: yes to the Upspin config. Doing upspin ls nf@wh3rd.net/pub/ succeeds with

nf@wh3rd.net/pub/Access
nf@wh3rd.net/pub/arnie.jpg
nf@wh3rd.net/pub/augie.jpg
nf@wh3rd.net/pub/augie.png
nf@wh3rd.net/pub/folk.mp3
nf@wh3rd.net/pub/nf - Evolving Wilds.mp3
nf@wh3rd.net/pub/upspin-servers-2017-10-30.txt

however, cacheserver reports the following:

$ cacheserver -log debug
2018/06/28 14:16:07.823502 rpc/dircache.readLogFile: /home/dominikh/upspin/dominik@honnef.co/dircache/clog.00000001
2018/06/28 14:16:07.824847 rpc/dircache.readLogFile: /home/dominikh/upspin/dominik@honnef.co/dircache/clog.00000002
2018/06/28 14:16:07.825992 rpc/dircache.readLogFile: /home/dominikh/upspin/dominik@honnef.co/dircache/clog.00000003
2018/06/28 14:16:07.827195 rpc/dircache.readLogFile: /home/dominikh/upspin/dominik@honnef.co/dircache/clog.00000004
2018/06/28 14:16:07.828947 rpc/dircache.rotateLog: new log file /home/dominikh/upspin/dominik@honnef.co/dircache/clog.00000005
2018/06/28 14:16:11.639397 rpc/storeserver: "dominik@honnef.co": store.Get("metadata:Health")
2018/06/28 14:16:11.639417 store/storecache: Get "metadata:Health"
2018/06/28 14:16:12.329765 rpc/dirserver: "dominik@honnef.co": dir.Lookup("nf@wh3rd.net/pub/")
2018/06/28 14:16:12.329790 dir/dircache: Lookup "nf@wh3rd.net/pub/"
2018/06/28 14:16:12.329826 dir/remote("").Dial("dominik@honnef.co", "remote,upspin.adg.tech:443")
2018/06/28 14:16:12.330036 dircache.Watcher nf@wh3rd.net remote,upspin.adg.tech:443
2018/06/28 14:16:12.330088 dir/remote("upspin.adg.tech:443").Watch("nf@wh3rd.net/" sequence -1)
2018/06/28 14:16:12.330891 rpc/dirserver: "dominik@honnef.co": dir.Glob("nf@wh3rd.net/pub/*")
2018/06/28 14:16:12.330912 dir/dircache: Glob "nf@wh3rd.net/pub/*"
2018/06/28 14:16:12.330957 dir/remote("upspin.adg.tech:443").Glob("nf@wh3rd.net/pub/*")
2018/06/28 14:16:13.696977 dir/dircache: Watch("nf@wh3rd.net/") started
2018/06/28 14:16:16.199802 dir/dircache: Watch("nf@wh3rd.net/") error: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:16.199840 dir/dircache.watcher: nf@wh3rd.net: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:17.200004 dir/remote("upspin.adg.tech:443").Watch("nf@wh3rd.net/" sequence -1)
2018/06/28 14:16:17.527098 dir/dircache: Watch("nf@wh3rd.net/") started
2018/06/28 14:16:19.773848 dir/dircache: Watch("nf@wh3rd.net/") error: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:19.773892 dir/dircache.watcher: nf@wh3rd.net: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:20.774035 dir/remote("upspin.adg.tech:443").Watch("nf@wh3rd.net/" sequence -1)
2018/06/28 14:16:21.086960 dir/dircache: Watch("nf@wh3rd.net/") started
2018/06/28 14:16:22.962251 dir/dircache: Watch("nf@wh3rd.net/") error: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:22.962288 dir/dircache.watcher: nf@wh3rd.net: item does not exist:
	store/remote("upspin.adg.tech:443").Get:
	fetching https://storage.googleapis.com/adg-tech-upspin-au/ED1E278671FC78953CD769FA5035731651D57C0BD98D35E9E4DCBAB78374AE3F: 404 Not Found
2018/06/28 14:16:23.962434 dir/remote("upspin.adg.tech:443").Watch("nf@wh3rd.net/" sequence -1)

I have truncated the output, because it keeps going seemingly forever (though I haven't kept it running forever, yet.)

Why does the Watch fail, and why does it keep retrying?

/cc @adg because it's his tree.