massive slowdown in 7.3.3

[mcol]

I've upgraded roxygen2 to 7.3.3 and running roxygen2::roxygenise() on the Luminescence package (https://github.com/R-Lum/Luminescence) went from 20 seconds to several minutes. At times (strangely enough, not always) I get tons of messages like this:

✖ Luminescence-generics.R:4: @description Could not resolve link to topic
  "RLum.Data-class" in the dependencies or base packages.
ℹ If you haven't documented "RLum.Data-class" yet, or just changed its name,
  this is normal. Once "RLum.Data-class" is documented, this warning goes
  away.
ℹ Make sure that the name of the topic is spelled correctly.
ℹ Always list the linked package as a dependency.
ℹ Alternatively, you can fully qualify the link with a package name.

I think I may be getting one such message for each link to any class or function defined in the package.

This may be similar to what is reported in #1720, but the analysis there doesn't seem to help in my case.

I've run a bisection, and it points to #1633. Indeed, commenting out the call to resolve_link_package() linked below removes the slowdown:

roxygen2/R/markdown-link.R

Line 150 in 145e7b4

if (is.na(pkg)) pkg <- resolve_link_package(obj, thispkg, state = state)

[mcol]

At times (strangely enough, not always) I get tons of messages like this

If I'm in a clean session and I do devtools::load_all(), the first time I run roxygenise() I don't get those errors. I've traced it to the fact that pkgload:::insert_global_shims() fully runs and sets up the help shims that are searched by roxygen2::has_topic().

However, if later in the session I run load_all() again, insert_global_shims() exits early. The help shims no longer work (presumably something else in devtools or pkgload has messed with them) so has_topic() starts returning FALSE thus generating those messages.

In any case, even if I hack markdown-link() to call pkgload:::insert_global_shims(force = TRUE), I still see the slowdown. In this case, has_topic() fails to find links to the base topics for character, list, data.frame and others.

[mcol]

In this case, has_topic() fails to find links to the base topics for character, list, data.frame and others.

This sounds similar to what has been reported in #1725.