Found the following significant warnings:
  LTRCforests.h:449:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:450:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:728:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:753:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1201:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1844:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1845:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1857:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1864:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1877:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1878:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1879:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1880:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1881:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1882:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:1951:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:2163:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:2165:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.h:2181:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:1485:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:1582:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:5806:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:6060:13: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  splitCustom.h:22:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:11915:16: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22014:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22320:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22729:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22764:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22778:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22815:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22823:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22846:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:22855:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:23736:11: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:27175:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:27188:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  LTRCforests.c:27372:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  splitCustom.c:22:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
See ‘/home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/LTRCforests.Rcheck/00install.out’ for details.
* used C compiler: ‘gcc-12 (Debian 12.2.0-10) 12.2.0’