Freeciv

mac-meson CI job (with a patch to enable werror):

FAILED: [code=1] libfc_server.a.p/server_savegame_savecompat.c.o 
cc -Ilibfc_server.a.p -I. -I.. -I../dependencies/luasql/src -I../dependencies/tinycthread -I../dependencies/tolua-5.2/include -I../dependencies/cvercmp -I../utility -I../common -I../common/networking -I../common/scriptcore -I../common/aicore -I../server -I../server/advisors -I../server/scripting -I../server/generator -I../server/ruleset -I../server/savegame -I../ai -I../ai/classic -I/opt/homebrew/include/lua -I/opt/homebrew/opt/gettext/include -I/opt/homebrew/opt/readline/include -fdiagnostics-color=always -Wall -Winvalid-pch -Werror -O0 -g -Wnested-externs -Wmissing-declarations -Wpointer-arith -Wcast-align -Wmissing-prototypes -Wformat -Wformat-security -Wshadow -Wold-style-definition -Wtype-limits -Wimplicit-fallthrough -DHAVE_CONFIG_H -MD -MQ libfc_server.a.p/server_savegame_savecompat.c.o -MF libfc_server.a.p/server_savegame_savecompat.c.o.d -o libfc_server.a.p/server_savegame_savecompat.c.o -c ../server/savegame/savecompat.c
../server/savegame/savecompat.c:432:34: error: variable length array folded to constant array as an extension [-Werror,-Wgnu-folding-constant]
  432 |       unsigned int known_row_old[lines * maxmapsize],
      |                                  ^~~~~~~~~~~~~~~~~~
../server/savegame/savecompat.c:433:30: error: variable length array folded to constant array as an extension [-Werror,-Wgnu-folding-constant]
  433 |                    known_row[lines * maxmapsize];
      |                              ^~~~~~~~~~~~~~~~~~
2 errors generated.