#289 debug build fails on current git master

[Erhard F.]

Tried to do a debug build (./configure --enable-debug) from current git-master (033b53179ba7a7f1d092be41bf85baab8ccb6f0b) which failed:

[...]
obj/cfg/linux/debug/v/draw.o (debug)
obj/cfg/linux/debug/linux/file.o (debug)
advance/linux/file.c: In function 'file_config_file_host':
advance/linux/file.c:188:68: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  188 |   snprintf(FL.file_host_buffer, sizeof(FL.file_host_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |                                                                    ^
advance/linux/file.c:188:3: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  188 |   snprintf(FL.file_host_buffer, sizeof(FL.file_host_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c: In function 'file_config_file_data':
advance/linux/file.c:213:69: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  213 |    snprintf(FL.file_data_buffer, sizeof(FL.file_data_buffer), "%s/%s", FL.data_dir_buffer, file);
      |                                                                     ^
advance/linux/file.c:213:4: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  213 |    snprintf(FL.file_data_buffer, sizeof(FL.file_data_buffer), "%s/%s", FL.data_dir_buffer, file);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c:208:69: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  208 |    snprintf(FL.file_data_buffer, sizeof(FL.file_data_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |                                                                     ^
advance/linux/file.c:208:4: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  208 |    snprintf(FL.file_data_buffer, sizeof(FL.file_data_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c: In function 'file_config_file_home':
advance/linux/file.c:228:68: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  228 |   snprintf(FL.file_home_buffer, sizeof(FL.file_home_buffer), "%s/%s", FL.home_dir_buffer, file);
      |                                                                    ^
advance/linux/file.c:228:3: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  228 |   snprintf(FL.file_home_buffer, sizeof(FL.file_home_buffer), "%s/%s", FL.home_dir_buffer, file);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c:223:68: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  223 |   snprintf(FL.file_home_buffer, sizeof(FL.file_home_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |                                                                    ^
advance/linux/file.c:223:3: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  223 |   snprintf(FL.file_home_buffer, sizeof(FL.file_home_buffer), "%s/%s", FL.current_dir_buffer, file + 2);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c: In function 'file_config_dir_multidir':
advance/linux/file.c:238:56: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  238 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s", FL.home_dir_buffer, tag);
      |                                                        ^
advance/linux/file.c:238:3: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  238 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s", FL.home_dir_buffer, tag);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c:236:56: warning: ':' directive output may be truncated writing 1 byte into a region of size between 0 and 511 [-Wformat-truncation=]
  236 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s:%s/%s", FL.home_dir_buffer, tag, FL.data_dir_buffer, tag);
      |                                                        ^
advance/linux/file.c:236:3: note: 'snprintf' output 4 or more bytes (assuming 1026) into a destination of size 512
  236 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s:%s/%s", FL.home_dir_buffer, tag, FL.data_dir_buffer, tag);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c: In function 'file_config_dir_singledir':
advance/linux/file.c:245:55: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  245 |  snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s", FL.home_dir_buffer, tag);
      |                                                       ^
advance/linux/file.c:245:2: note: 'snprintf' output 2 or more bytes (assuming 513) into a destination of size 512
  245 |  snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s/%s", FL.home_dir_buffer, tag);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
advance/linux/file.c: In function 'file_config_dir_singlefile':
advance/linux/file.c:252:54: warning: '%s' directive output may be truncated writing up to 511 bytes into a region of size between 0 and 511 [-Wformat-truncation=]
  252 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s:%s", FL.home_dir_buffer, FL.data_dir_buffer);
      |                                                      ^~                       ~~~~~~~~~~~~~~~~~~
advance/linux/file.c:252:3: note: 'snprintf' output between 2 and 1024 bytes into a destination of size 512
  252 |   snprintf(FL.dir_buffer, sizeof(FL.dir_buffer), "%s:%s", FL.home_dir_buffer, FL.data_dir_buffer);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
obj/cfg/linux/debug/linux/target.o (debug)
obj/cfg/linux/debug/linux/os.o (debug)
obj/cfg/linux/debug/linux/vcurses.o (debug)
obj/cfg/linux/debug/linux/itty.o (debug)
obj/cfg/linux/debug/linux/vfb.o (debug)
obj/cfg/linux/debug/advcfg (debug)
/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: obj/cfg/linux/debug/blit/blit.o: in function `interp_16_dist3':
/root/build/advancemame/advance/blit/interp.h:494: undefined reference to `interp_16_dist'
/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /root/build/advancemame/advance/blit/interp.h:494: undefined reference to `interp_16_dist'
collect2: error: ld returned 1 exit status
make: *** [advance/cfg.mak:271: obj/cfg/linux/debug/advcfg] Error 1

Building without --enable-debug works fine.