[feature] Show "Unable to find" packages in conan graph

[KUGA2]

What is your suggestion?

When I do a simple example package, add a dependency that it can not resolve, then this dependency does not appear in graph. So I can not know where this dependency comes from. In my example, it is pretty clear where the problem comes from, but if you got multiple dependencies its not quite so simple.
My feature request is that these packages should also be shown in html, but in a different color / shape. This would help finding where this dependency comes from.

Reproduction:

• Create new project in windows: conan new cmake_exe -d name=example -d version=0.1
• Add:

    def requirements(self):
        self.requires("libpcap/[>=1.10.3 <2]")

• Have pcap recipe but not winflexbison recipe in cache (and remotes)
• Run: conan graph info . -f html --out-file=graph.html

Result:

ERROR: Package 'winflexbison/2.5.25' not resolved: Unable to find 'winflexbison/2.5.25' in remotes.

Expected result:

Have you read the CONTRIBUTING guide?

• I've read the CONTRIBUTING guide

[AbrilRBS]

Hi @KUGA2 thhanks for your request. We have implemented #19360 for Conan 2.24 with exactly this feature :)