does not compile under Raspbian Trixie [FIX]

[sp9wpn]

While trying to build csdr on latest rasbian:

pi@rpi:/tmp/csdr/build$ cmake ..
[...]
-- Build files have been written to: /tmp/csdr/build
pi@rpi:/tmp/csdr/build$ make
[  1%] Building C object src/CMakeFiles/csdr.dir/libcsdr.c.o
/tmp/csdr/src/libcsdr.c:401:9: note: ‘#pragma message: Manual NEON (aarch64) optimizations are ON: we have a faster shift_addfast_cc now.’
  401 | #pragma message "Manual NEON (aarch64) optimizations are ON: we have a faster shift_addfast_cc now."
      |         ^~~~~~~
/tmp/csdr/src/libcsdr.c: In function ‘fir_decimate_init’:
/tmp/csdr/src/libcsdr.c:564:5: error: implicit declaration of function ‘errhead’; did you mean ‘pread’? [-Wimplicit-function-declaratio]
  564 |     errhead(); fprintf(stderr,"taps_length = %d\n", result.taps_length);
      |     ^~~~~~~
      |     pread
/tmp/csdr/src/libcsdr.c: At top level:
/tmp/csdr/src/libcsdr.c:655:9: note: ‘#pragma message: Manual NEON (aarch64) optimizations are ON: we have a faster fir_decimate_cc now’
  655 | #pragma message "Manual NEON (aarch64) optimizations are ON: we have a faster fir_decimate_cc now."
      |         ^~~~~~~
make[2]: *** [src/CMakeFiles/csdr.dir/build.make:79: src/CMakeFiles/csdr.dir/libcsdr.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:177: src/CMakeFiles/csdr.dir/all] Error 2
make: *** [Makefile:136: all] Error 2

pi@rpi:/tmp/csdr/build$ uname -a
Linux rpi-hq 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux

[sp9wpn]

Ok, fixe is easier than I expected. Just add:

int errhead();

at the start of src/libcsdr.c