Error while generating NEWS

[lionel-]

https://github.com/tidyverse/purrr/runs/922354204?check_suite_focus=true#step:9:211

pkgdown::build_news()
── Building news ────────────────────────────────────────────────────────────────────────
Error: `x` must be a package name or a function inheriting from a namespace.
Run `rlang::last_error()` to see where the error occurred.
Run `rlang::last_error()` to see where the error occurred.

rlang::last_trace()
#> Backtrace:
#>      █
#>   1. └─pkgdown::build_news()
#>   2.   └─pkgdown:::build_news_single(pkg)
#>   3.     └─pkgdown:::data_news(pkg)
#>   4.       └─pkgdown:::markdown(path(pkg$src_path, "NEWS.md"))
#>   5.         └─downlit::downlit_html_node(xml)
#>   6.           └─downlit:::tweak_children(x, xpath_inline, autolink, replace = "contents")
#>   7.             └─downlit:::map_chr(text, fun, ...)
#>   8.               └─base::vapply(.x, .f, ..., FUN.VALUE = character(1), USE.NAMES = FALSE)
#>   9.                 └─downlit:::FUN(X[[i]], ...)
#>  10.                   └─downlit::autolink_url(text)
#>  11.                     └─downlit:::href_expr(expr[[1]])
#>  12.                       └─downlit::href_topic(fun_name, pkg)
#>  13.                         └─downlit:::href_topic_local(topic)
#>  14.                           └─downlit:::href_topic_reexported(topic, getOption("downlit.package"))
#>  15.                             └─downlit:::find_reexport_source(obj, ns, topic)
#>  16.                               └─rlang::ns_env_name(get_env(obj))
#>  17.                                 └─rlang::ns_env(x)
#>  18.                                   └─rlang::abort("`x` must be a package name or a function inheriting from a namespace.")
#>  19.                                     └─rlang:::signal_abort(cnd)

Digging down the rabbit hole, it appears it's because purrr reexports is_null() from rlang. This symbol is an alias for is.null() so obj contains a primitive function here:

find_reexport_source(is.null, ns_env("purrr"), "is_null")
#> Error: `x` must be a package name or a function inheriting from a namespace.

[lionel-]

hmm the problem is in rlang. get_env() should return the base namespace rather than the base env with primitive functions:

rlang::get_env(is.null)
#> <environment: base>

rlang::ns_env(is.null)
#> <environment: namespace:base>

[lionel-]

Fixed in r-lib/rlang@1fb41d7 but I'll leave this open in case you want to add a unit test.