* installing *source* package ‘jgd’ ...
** this is package ‘jgd’ version ‘0.1.0’
** using staged installation
** libs
using C compiler: ‘Debian clang version 21.1.8 (3+b1)’
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c init.c -o init.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c device.c -o device.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c callbacks.c -o callbacks.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c display_list.c -o display_list.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c transport.c -o transport.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c metrics.c -o metrics.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c color.c -o color.o
clang-21 -std=gnu23 -I"/home/hornik/tmp/R-d-clang-21/include" -DNDEBUG -Icjson  -I/usr/local/include -DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c png_encoder.c -o png_encoder.o
clang-21 -std=gnu23 -shared -L/home/hornik/tmp/R-d-clang-21/lib -Wl,-O1 -o jgd.so init.o device.o callbacks.o display_list.o transport.o metrics.o color.o png_encoder.o cjson/cJSON.o -L/home/hornik/tmp/R-d-clang-21/lib -lR
cjson/cJSON.o: file not recognized: file format not recognized
clang-21: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [/home/hornik/tmp/R-d-clang-21/share/make/shlib.mk:10: jgd.so] Error 1
ERROR: compilation failed for package ‘jgd’
* removing ‘/srv/hornik/tmp/CRAN_pretest/jgd.Rcheck/jgd’