Valid DOI redirected links trigger warnings.

[charleskawczynski]

I'm seeing lots of doc warnings regarding redirected DOI links. For example

┌ Warning: linkcheck 'https://doi.org/10.1016/0169-8095%2894%2900090-Z' status: 302, redirects to https://linkinghub.elsevier.com/retrieve/pii/016980959400090Z.
└ @ Documenter.DocChecks ~/.julia/packages/Documenter/PLD7m/src/DocChecks.jl:223

Both the first and second links work. It doesn't seem like this should be a warning.

[simonbyrne]

It's especially confusing since in this case since they trigger an @warn, but don't actually cause a linkcheck failure:

Documenter.jl/src/DocChecks.jl

Lines 222 to 226 in 8e53b7b

	if location !== nothing
	@warn "linkcheck '$(link.url)' status: $(status), redirects to $(location)."
	else
	@warn "linkcheck '$(link.url)' status: $(status)."
	end

whereas other errors that do trigger linkcheck failures sometimes trigger an @warn:

Documenter.jl/src/DocChecks.jl

Lines 236 to 237 in 8e53b7b

	push!(doc.internal.errors, :linkcheck)
	@warn "invalid result returned by $cmd:" result

and sometimes an @error:

Documenter.jl/src/DocChecks.jl

Lines 232 to 233 in 8e53b7b

	push!(doc.internal.errors, :linkcheck)
	@error "linkcheck '$(link.url)' status: $(status)."

Would it be possible to make them so that any linkcheck failures always trigger an @error?

[simonbyrne]

In this specific case, I don't think 302 errors should trigger a warning, since it is meant to be used as a temporary redirect:
https://en.wikipedia.org/wiki/HTTP_302

[mortenpi]

Would it be possible to make them so that any linkcheck failures always trigger an @error?

An argument one could make is that e.g. with 301 redirects the links are still technically working, so we shouldn't error on them.

[simonbyrne]

I meant any failure which does push!(doc.internal.errors, :linkcheck)

[charleskawczynski]

An argument one could make is that e.g. with 301 redirects the links are still technically working, so we shouldn't error on them.

But is warning the best option? Can’t we check the redirected link and warn/error if it’s broken and pass otherwise? @mortenpi

[mortenpi]

Can’t we check the redirected link and warn/error if it’s broken and pass otherwise?

That's an additional step, that we actually follow the 3XX redirects. We could definitely do that if someone wants to take a stab at implementing this.

[charleskawczynski]

Ok. Should we reopen this issue, then?

[mortenpi]

Perhaps a new one? The DOI/302 issue has been resolved (temporary redirects do not print a warning nor an error).