Add the InteractiveUtils.diagnostics() and InteractiveUtils.stdlib_diagnostics() functions

[DilumAluthge]

• Needs #43807

This PR is an attempt to create an "all-in-one" debugging function that dumps as much debugging information as possible. That way, when a user opens a new bug report, instead of needing to run ten or twenty different commands, they can just run a single command (InteractiveUtils.diagnostics()) and post the output of that command (after confirming that the output does not contain any information that should not be shared publicly).

[DilumAluthge]

A while ago on Slack, @GunnarFarneback suggested having a Pkg.diagnostics() function that would print out the following information:

• What package server is configured (if any)
• Whether the package server is operational
• If it's not, why, to the extent it can be determined. (Proxy error, server down, bad host name, whatever.)
• What kind of registry is being used (git, unpacked from package server, compressed tar)
• Possibly detecting known registry failure modes (git registry dirty, unpacked registry incomplete)
• What environment variables influencing Pkg behavior are set

I think that it might be good to add that information to the InteractiveUtils.diagnostics() function in this PR, instead of creating a new Pkg-specific Pkg.diagnostics() function. That way, the user experience is easier; the user just needs to run a single function InteractiveUtils.diagnostics() and post its output (after confirming that the output does not contain any information that should not be shared publicly).

[vtjnash]

This seems like a good idea to me. I wonder if we could do this as a hook-type system, so that this function is just a little stub which is implemented as:

function diagnostics(io=stdout)
    println(io, "# header info:")
    println(io, " ?")
    for m in sort!(Base.loaded_modules_array(), by=nameof)
        if isdefined(m, :__diagnostics__) && applicable(m.__diagnostics__, io)
            println(io, "# " nameof(m))
            println(io, "-"^length(String(nameof(m)))
            m.__diagnostics__(io)
            println()
        end
    end
    println(io, "# footer info")
    println(io, " ?")
end

[DilumAluthge]

I like the idea of the hook-type system. I've implemented that approach here. I've also made a few PRs to external stdlibs to add __diagnostics__ functions to those stdlibs:

1. Add the NetworkOptions.__diagnostics__() function NetworkOptions.jl#21
2. Add the Pkg.__diagnostics__() function Pkg.jl#2992

[vtjnash]

Suggested change

	Base.showerror(io, ex)
	Base.show_backtrace(io, bt)
	Base.showerror(io, catch_stack())

[DilumAluthge]

Per https://docs.julialang.org/en/v1.8-dev/base/base/#Base.current_exceptions, it looks like catch_stack() has been renamed in 1.7 and later?

[JeffBezanson]

Seems ok to me. Request from @StefanKarpinski : return a TOML-compatible data structure that prints nicely, so it can be processed programmatically. versioninfo can be migrated to that as well; where necessary the value for a key can just be a big string to make it easier. Specifically: __diagnostics__ can return Dicts, diagnostics can call TOML to print it nicely.