I can confirm this Rd warning in R-devel (2021-04-23 r80216), but not in
R 4.0.5. It happens when installing the static help (INSTALL option --html).
The following R code reproduces the warning by creating a tiny test
package and then calling relevant internal functions from 'tools':
```R
## cre
Hi all,
Since R 4.1, R CMD INSTALL throws warning during building the man pages, when
installing from source.
We noticed this first on Windows for man pages involving S4 replacement
function:
*
http://bioconductor.org/checkResults/devel/bioc-LATEST/Modstrings/riesling1-checksrc.html
*
