* installing to library ‘/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages’
* installing *source* package ‘vws’ ...
** this is package ‘vws’ version ‘0.3.0’
** package ‘vws’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
using C++ compiler: ‘Debian clang version 22.1.8 (1+b1)’
make[1]: Entering directory '/home/hornik/tmp/scratch/RtmpvXfSnz/R.INSTALL10a9df25c8e79/vws/src'
clang++-22 -std=gnu++20 -I"/home/hornik/tmp/R.check/r-devel-clang/Work/build/include" -DNDEBUG -I../inst/include -I. -I'/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/Rcpp/include' -I'/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/fntl/include' -I/usr/local/include -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic   -c RcppExports.cpp -o RcppExports.o
In file included from RcppExports.cpp:4:
In file included from ./../inst/include/vws.h:17:
In file included from ./../inst/include/FMMProposal.h:5:
In file included from ./../inst/include/typedefs.h:6:
./../inst/include/optimize-hybrid.h:104:22: error: no member named 'to_underlying' in namespace 'fntl'
  104 |                 out.status = fntl::to_underlying(opt_out.status);
      |                                    ^~~~~~~~~~~~~
In file included from RcppExports.cpp:4:
In file included from ./../inst/include/vws.h:17:
./../inst/include/FMMProposal.h:243:16: warning: unused variable 'L' [-Wunused-variable]
  243 |                 unsigned int L = _regions.size();
      |                              ^
./../inst/include/FMMProposal.h:236:15: warning: unused variable 'N' [-Wunused-variable]
  236 |         unsigned int N = knots.size() + 1;
      |                      ^
In file included from RcppExports.cpp:4:
In file included from ./../inst/include/vws.h:27:
In file included from ./../inst/include/rejection.h:10:
./../inst/include/rejection-args.h:99:33: error: no member named 'to_underlying' in namespace 'fntl'
   99 |                 Rcpp::Named("action") = fntl::to_underlying(action)
      |                                               ^~~~~~~~~~~~~
2 warnings and 2 errors generated.
make[1]: *** [/home/hornik/tmp/R.check/r-devel-clang/Work/build/etc/Makeconf:197: RcppExports.o] Error 1
make[1]: Leaving directory '/home/hornik/tmp/scratch/RtmpvXfSnz/R.INSTALL10a9df25c8e79/vws/src'
ERROR: compilation failed for package ‘vws’
* removing ‘/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/vws’