Found the following significant warnings:
  ./cmdline.h:30:2: warning: embedding a directive within macro arguments has undefined behavior [-Wembedded-directive]
  ./cmdline.h:32:2: warning: embedding a directive within macro arguments has undefined behavior [-Wembedded-directive]
See ‘/data/gannet/ripley/R/packages/tests-clang/moocore.Rcheck/00install.out’ for details.
* used C compiler: ‘clang version 18.1.8’
Installation failed.
See ‘/data/gannet/ripley/R/packages/tests-devel/moocore.Rcheck/00install.out’ for details.
Installation failed.
See ‘/Volumes/Builds/packages/big-sur-x86_64/results/4.4/moocore.Rcheck/00install.out’ for details.
Installation failed.
See ‘/Volumes/Builds/packages/big-sur-x86_64/results/4.3/moocore.Rcheck/00install.out’ for details.