>> Has anybody been in contact with lua folks?
> I sent email now.

The thread starts here.

Skimming the thread, I don't see an obvious conclusion. I take it updating to Lua 5.1.5 didn't happen to fix this?

(This ticket is currently targeted at 2.3.2.)

This clearly isn't going to make 2.3.1, but is still desirable to fix on S2_3 for portability.

can't close the ticket as the applied patch does NOT fix the bug - it's only (perhaps) a helper to find the reason

The attached patch adds a lua api check if debugging is activated. perhaps this allows us to find the reason for the lua error ...

(file #14078)

Here we go, I believe this is the source of the SIGBUS. 2.2 works fine on sparc64, here is what changed:
2.3:
./utility/registry.c:1952: int *secfile_lookup_int_vec(const struct section_file *secfile, ./utility/registry.c:1953: size_t *dim, const char *path, ...) ... 3230 food_ini = secfile_lookup_int_vec(file, (size_t *) 3231 &game.info.granary_num_inis, 3232 "civstyle.granary_food_ini"); 2.2:
./utility/registry.c:1606: int *secfile_lookup_int_vec(struct section_file *my_section_file, ./utility/registry.c:1607: int *dimen, const char *path, ...) ... 3082 food_ini = secfile_lookup_int_vec(&file, &game.info.granary_num_inis, 3083 "civstyle.granary_food_ini");

The function secfile_lookup_int_vec() is now broken (it was good in 2.2).

I think this is what is called "strict alignment". n-byte data types must be n-byte aligned. game.info.granary_num_inis is 4-byte aligned, and when cast to a 8-byte data type causes the SIGBUS.

It does not make the warning go away. The attached diff does, however I have no idea what consequences it might have. I don't use LUA, I can't really test it.

You split this bug report in two, however the following is relevant to both of them:

cc1: warnings being treated as errors
ruleset.c: In function 'load_ruleset_game':
ruleset.c:3231: warning: cast increases required alignment of target type

And ruleset.c:3231 is:

3230 food_ini = secfile_lookup_int_vec(file, (size_t *)
3231 &game.info.granary_num_inis,
3232 "civstyle.granary_food_ini");

secfile_lookup_int_vec, where the bus error occurs.

The attached diff makes the warnings go away, but not the problem. I believe the "patched" lua code will produce more bus errors, regardless of the type the pointers are cast to. The solution to this is make a temporary variable, and copy stuff to it. That way it will be aligned. If not that, then add some _alignment_ (8) attribute to that LUA struct.

Here is a relevant document: http://cmynhier.blogspot.com/2008/10/memory-alignment-on-sparc-or-300x.html

(file #13833)

Reported by Michal Mazurek <akfaew> as part of bug #18468:

cc1: warnings being treated as errors
ldebug.c: In function 'luaG_errormsg':
ldebug.c:620: warning: cast increases required alignment of target type
gmake[4]: *** [ldebug.o] Error 1
gmake[4]: Leaving directory `/home/longturn/src/freeciv-2.3.0/dependencies/lua-5.1/src'
gmake[3]: *** [all-recursive] Error 1
gmake[3]: Leaving directory `/home/longturn/src/freeciv-2.3.0/dependencies/lua-5.1'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/home/longturn/src/freeciv-2.3.0/dependencies'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/home/longturn/src/freeciv-2.3.0'
gmake: *** [all] Error 2