It is wrong to save empty available versions as cache when connection failed

[zhangkaizhao]

connection failed:

% curl -v https://nodejs.org/dist/index.json
* Host nodejs.org:443 was resolved.
* IPv6: 2606:4700:10::6814:162e, 2606:4700:10::6814:172e
* IPv4: 104.20.23.46, 104.20.22.46
*   Trying 104.20.23.46:443...
*   Trying [2606:4700:10::6814:162e]:443...
* Immediate connect fail for 2606:4700:10::6814:162e: No route to host
*   Trying [2606:4700:10::6814:172e]:443...
* Immediate connect fail for 2606:4700:10::6814:172e: No route to host
* connect to 104.20.23.46 port 443 from 192.168.31.38 port 58385 failed: Operation timed out
*   Trying 104.20.22.46:443...
* connect to 104.20.22.46 port 443 from 192.168.31.38 port 58395 failed: Operation timed out
* Failed to connect to nodejs.org port 443 after 150188 ms: Couldn't connect to server
* Closing connection
curl: (28) Failed to connect to nodejs.org port 443 after 150188 ms: Couldn't connect to server

but vfox with nodejs plugin saves empty available versions as cache:

% rm -f .version-fox/plugin/nodejs/available.cache
% vfox --debug search nodejs
CallFunction: Available
Available hook cache duration: 12h
Available hook cache key: empty, hit: false 
# -> NOTE: here wait for a long time to timeout
no available version
% hexyl .version-fox/plugin/nodejs/available.cache 
┌────────┬─────────────────────────┬─────────────────────────┬────────┬────────┐
│00000000│ 0f ff 81 04 01 02 ff 82 ┊ 00 01 0c 01 ff 80 00 00 │•×ו••××┊⋄•_•××⋄⋄│
│00000010│ 1e 7f 03 01 02 ff 80 00 ┊ 01 02 01 03 56 61 6c 01 │•••••××⋄┊••••Val•│
│00000020│ 0a 00 01 06 45 78 70 69 ┊ 72 65 01 04 00 00 00 19 │_⋄••Expi┊re••⋄⋄⋄•│
│00000030│ ff 82 00 01 05 65 6d 70 ┊ 74 79 01 02 5b 5d 01 f8 │××⋄••emp┊ty••[]•×│
│00000040│ 2f e6 61 57 93 68 6f c0 ┊ 00                      │/×aW×ho×┊⋄       │
└────────┴─────────────────────────┴─────────────────────────┴────────┴────────┘
% vfox --debug search nodejs                      
CallFunction: Available
Available hook cache duration: 12h
Available hook cache key: empty, hit: true 
# -> NOTE: here now use available cache immediately
no available version

nodejs plugin info:

% vfox info nodejs
Plugin Info:
Name     -> nodejs
Version  -> 0.3.0
Homepage -> https://github.com/version-fox/vfox-nodejs
Desc     ->
Node.js runtime environment.
Legacy Files -> [.node-version .nvmrc]

expected:
Just show error output and no need to save anything as cache when connection failed.