dub: Could not resolve configuration for package demo

[Inkrementator]

On Friday, 15 March 2024 at 17:48:26 UTC, mw wrote:
> ```
> $ dub build
> Could not resolve configuration for package demo
> ```

Trying to build your dependency msgpack-rpc, it spits out
```
      Warning The sub configuration directive "vibe-d" -> 
[libevent] references a configuration that does not exist.
Error Could not resolve configuration for package msgpack-rpc
```
In version 0.7, vibe-d depended on libevent, this got removed in 
the meantime
https://github.com/vibe-d/vibe.d/commit/196096407ec27b2c107f0038c6751ce07e7a9507

Just patching msgpack-rpc dub.json to use the exact vibe-d 
version, and not a minimum, like this
```json
	"dependencies": {
		"msgpack-d": ">=0.9.2",
		"vibe-d": "==0.7.25"
	},
```
fails too, because this old vibe-d version doesn't compile 
anymore.

You'll have to either fix the old vibe-d version, or fork 
msgpack-rpc to work with current vibe-d, whatever is more 
appropriate and easier.