Found the following significant warnings:
  base_radixsort.c:448:14: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:464:14: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:1134:15: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:1172:9: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:1263:27: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:1779:22: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  base_radixsort.c:1784:22: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:54:136: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:67:68: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:68:74: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:70:80: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:71:103: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:72:102: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:72:116: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:73:78: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:74:76: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:75:84: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:76:74: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:77:76: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:78:76: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:79:78: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
  data.table_init.c:83:92: warning: format specifies type 'int' but the argument has type 'R_xlen_t' (aka 'long') [-Wformat]
  data.table_rbindlist.c:247:125: warning: format specifies type 'int' but the argument has type 'int64_t' (aka 'long') [-Wformat]
  data.table_rbindlist.c:256:106: warning: format specifies type 'int' but the argument has type 'int64_t' (aka 'long') [-Wformat]
  data.table_rbindlist.c:397:37: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
  data.table_rbindlist.c:678:31: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
  data.table_subset.c:507:28: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
  data.table_subset.c:615:28: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
See ‘/home/hornik/tmp/R.check/r-devel-clang/Work/PKGS/collapse.Rcheck/00install.out’ for details.
* used C compiler: ‘Debian clang version 17.0.5 (1)’
* used C++ compiler: ‘Debian clang version 17.0.5 (1)’