build_reference(): a function cannot share the package's name

[Rmomal]

The build_reference() function gives an error I did not have before a recent update:
Error: Failed to parse Rd in myfunction.Rd ℹ values must be length 1, but FUN(X[[1]]) result is length 2
I wasn't able to fully understand the error, but finally figured that it was due to my function having the same name as my package. Changing it did the trick, however I guess it is not a weird name and it should be allowed. Is there a way to do so ?

Here is the traceback:

> traceback()
17: stop(fallback)
16: signal_abort(cnd)
15: abort(msg, parent = err)
14: h(simpleError(msg, call))
13: .handleSimpleError(function (err) 
    {
        msg <- c(paste0("Failed to parse Rd in ", topic$file_in), 
            i = err$message)
        abort(msg, parent = err)
    }, "values must be length 1,\n but FUN(X[[1]]) result is length 2", 
        base::quote(vapply(.x, .f, ..., FUN.VALUE = character(1), 
            USE.NAMES = FALSE)))
12: vapply(.x, .f, ..., FUN.VALUE = character(1), USE.NAMES = FALSE)
11: map_chr(text[fun], href_topic_local)
10: token_href(out$token, out$text)
9: downlit::highlight(text, classes = downlit::classes_pandoc())
8: highlight_text(text)
7: as_data.tag_usage(tags$tag_usage[[1]])
6: as_data(tags$tag_usage[[1]])
5: data_reference_topic(topic, pkg, examples = examples, run_dont_run = run_dont_run)
4: withCallingHandlers(data_reference_topic(topic, pkg, examples = examples, 
       run_dont_run = run_dont_run), error = function(err) {
       msg <- c(paste0("Failed to parse Rd in ", topic$file_in), 
           i = err$message)
       abort(msg, parent = err)
   })
3: .f(.x[[i]], ...)
2: purrr::map(topics, build_reference_topic, pkg = pkg, lazy = lazy, 
       examples = examples, run_dont_run = run_dont_run)
1: pkgdown::build_reference()

[maelle]

I can reproduce this with the desc package (that has a function called desc()) if I add a package man page (otherwise, it works fine). Both desc.Rd and desc-package.Rd share the alias "desc". I wonder whether this is something that should be solved in roxygen2, should the @PACKAGE tag not add the alias if there's another man page with the alias? 🤔

[maelle]

Especially as R CMD check warns about duplicate aliases (so downlit doesn't expect find_rdname() to return two Rd names).

[alexpghayes]

Just ran into this as well and followed Davis' advice at tidymodels/hardhat#130 (comment) for a temporary workaround in https://github.com/RoheLab/vsp.

Attempted fix: RoheLab/vsp@cdd1799

[hadley]

This seems more like a roxygen2 issue than a downlit one, given the R CMD check warning.

[maelle]

There is even already an issue there r-lib/roxygen2#1160

[rhijmans]

I encountered this error because I had the same alias for a method twice in the same Rd file (I do not use roxygen). It was not the same as the package name; and R CMD check apparently does not not catch that. It was difficult to find what caused it because the duplication was not in the Rd file where the pkdown compilation broke. The compilation broke in another Rd that used the offending method in the example. It would have been very helpful to get an error message telling me which value had length 2.

[maelle]

@rhijmans Thank you! This has been fixed by 1fe9140 so no need for a new error message now. 😁

[maelle]

unless I misunderstood your comment, in which case it'll be easier to open a new issue I think.