* installing *source* package ‘intervals’ ...
** using staged installation
** libs
using C compiler: ‘Debian clang version 18.1.8 (9)’
using C++ compiler: ‘Debian clang version 18.1.8 (9)’
clang++-18  -std=gnu++17 -I"/home/hornik/tmp/R-d-clang-18/include" -DNDEBUG   -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3 -DSTRICT_R_HEADERS=1  -fpic  -g -O3 -Wall -pedantic -DR_NO_REMAP -c Endpoint.cpp -o Endpoint.o
clang-18  -I"/home/hornik/tmp/R-d-clang-18/include" -DNDEBUG   -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3 -DSTRICT_R_HEADERS=1  -fpic  -g -O3 -Wall -pedantic -c init.c -o init.o
clang++-18  -std=gnu++17 -I"/home/hornik/tmp/R-d-clang-18/include" -DNDEBUG   -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3 -DSTRICT_R_HEADERS=1  -fpic  -g -O3 -Wall -pedantic -DR_NO_REMAP -c plot_overlap.cpp -o plot_overlap.o
clang++-18  -std=gnu++17 -I"/home/hornik/tmp/R-d-clang-18/include" -DNDEBUG   -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3 -DSTRICT_R_HEADERS=1  -fpic  -g -O3 -Wall -pedantic -DR_NO_REMAP -c reduce.cpp -o reduce.o
clang++-18  -std=gnu++17 -I"/home/hornik/tmp/R-d-clang-18/include" -DNDEBUG   -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3 -DSTRICT_R_HEADERS=1  -fpic  -g -O3 -Wall -pedantic -DR_NO_REMAP -c which_nearest.cpp -o which_nearest.o
which_nearest.cpp:134:22: error: use of undeclared identifier 'length'
  134 |             if (it->index < length(qe) && *q_pending.begin() < length(qe) ) {
      |                             ^
which_nearest.cpp:134:57: error: use of undeclared identifier 'length'
  134 |             if (it->index < length(qe) && *q_pending.begin() < length(qe) ) {
      |                                                                ^
2 errors generated.
make: *** [/home/hornik/tmp/R-d-clang-18/etc/Makeconf:202: which_nearest.o] Error 1
ERROR: compilation failed for package ‘intervals’
* removing ‘/srv/hornik/tmp/CRAN/intervals.Rcheck/intervals’