Fails to configure with compiler flags that Apple will start using:
See the configure logs at
https://www.stats.ox.ac.uk/pub/bdr/NoImplicitDecl/
These are the config.log from installing the package on a Linux machine
with the C compiler flag -Werror=implicit-function-declaration and
indicate problems with your configure script. You should see a similar
warning even without that flag.
The reason for looking at these now is that Apple has (essentially)
added that flag by default in the toolchain (12.x) it released earlier
this month, and so configure may not work as you intended on Macs with
that toolchain. There are comments in the logs which indicate the
corrections needed.
Other toolchains may follow suit: there has been a bug report on gcc for
quite some time and careful users may already be adding this flag.
Please correct before 2020-12-08 to safely retain your package on CRAN.
Fails to configure with compiler flags that Apple will start using: