* installing to library ‘/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages’
* installing *source* package ‘PRTree’ ...
** package ‘PRTree’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
using C compiler: ‘Debian clang version 18.1.4 (1)’
using Fortran compiler: ‘Debian flang-new version 18.1.4 (1)’
make[1]: Entering directory '/tmp/Rtmpa3WiwA/R.INSTALL375797254a967a/PRTree/src'
clang-18 -I"/home/hornik/tmp/R.check/r-devel-clang/Work/build/include" -DNDEBUG   -I/usr/local/include -D_FORTIFY_SOURCE=3   -fpic  -g -O3 -Wall -pedantic -c PRTree_init.c -o PRTree_init.o
flang-new-18  -fpic  -g -O2 -c  base.f90 -o base.o
error: loc("/tmp/Rtmpa3WiwA/R.INSTALL375797254a967a/PRTree/src/base.f90":377:14): 'arith.addi' op requires the same type for all operands and results
error: verification of lowering to FIR failed
make[1]: *** [/home/hornik/tmp/R.check/r-devel-clang/Work/build/etc/Makeconf:223: base.o] Error 1
make[1]: Leaving directory '/tmp/Rtmpa3WiwA/R.INSTALL375797254a967a/PRTree/src'
ERROR: compilation failed for package ‘PRTree’
* removing ‘/home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/PRTree’