error loading mdoule 'ffi': undefined symbol: lua_getiuservalue

[Robin-Sch]

Hello everyone!

I just installed lua-vips, however, I constantly get the following error:

error loading mdoule 'ffi': undefined symbol: lua_getiuservalue

could you please help me out how to debug this? Thanks a lot!

[jcupitt]

Hello @Robin-Sch,

Which Lua version is this, and which platform are you using?

lua_getiuservalue ought to be in current Lua, I think:

https://www.lua.org/manual/5.4/manual.html#lua_getiuservalue

If you cannot link to it, perhaps you are missing the Lua dev package?

[Robin-Sch]

I am using arch linux, lua version 5.4.7. How do I get the dev package?

[jcupitt]

Sorry, I don't know arch too well. Maybe ask on their support?

[Robin-Sch]

I have not too much experience with lua, but I think everything should already be installed perfect fine: https://wiki.archlinux.org/title/Lua

[rolandlo]

@Robin-Sch How exactly did you install lua-vips and how do you use it?

One observation: lua_getiuservalue is only available in Lua 5.4, not in earlier Lua versions.
On my system (on which lua is for version 5.3):

strings $(which lua) | grep uservalue

returns

lua_setuservalue
lua_getuservalue
getuservalue
setuservalue

whereas

strings $(which lua5.4) | grep uservalue

returns

lua_setiuservalue
lua_getiuservalue
getuservalue
setuservalue

So first check if the symbol is available in your Lua binary.

Further you could try debugging like this:

1. Run the GNU debugger via gdb lua5.4 (or gdb lua depending on the name of the Lua 5.4 binary on your system)
2. Enter break lua_getiuservalue into the debugger console (and confirm with the Enter key). I get

(gdb) break lua_getiuservalue                                                   
Downloading source file /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c
Haltepunkt 1 at 0xb740: file /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c, line 802.

3. Enter run into the debugger console. Now the Lua console should start running.
4. Enter vips = require "vips" into the Lua console. I get

Downloading separate debug info for /usr/local/lib/lua/5.4/ffi.so
                                                                                
Breakpoint 1, lua_getiuservalue (L=0x55555559e2a8, idx=-1, n=1)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c:802
Warnung: 802	/build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c: Datei oder Verzeichnis nicht gefunden

5. Enter bt to get a backtrace. I get

#0  lua_getiuservalue (L=0x55555559e2a8, idx=-1, n=1)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c:802
#1  0x00007ffff7fa7e01 in parse_type () from /usr/local/lib/lua/5.4/ffi.so
#2  0x00007ffff7f9cfa0 in add_typedef () from /usr/local/lib/lua/5.4/ffi.so
#3  0x00007ffff7f9e092 in setup_upvals () from /usr/local/lib/lua/5.4/ffi.so
#4  0x000055555556432a in precallC (f=<optimised out>, nresults=0, 
    func=0x5555555e2b50, L=0x55555559e2a8)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/ldo.c:529
#5  luaD_precall (L=L@entry=0x55555559e2a8, func=<optimised out>, 
    nresults=nresults@entry=0)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/ldo.c:595
#6  0x0000555555564e65 in ccall (inc=65537, nResults=0, func=<optimised out>, 
    L=0x55555559e2a8) at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/ldo.c:635
#7  luaD_callnoyield (nResults=0, func=<optimised out>, L=0x55555559e2a8)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/ldo.c:655
#8  lua_callk (L=0x55555559e2a8, nargs=<optimised out>, nresults=0, 
    ctx=<optimised out>, k=<optimised out>)
    at /build/lua5.4-GCEpSw/lua5.4-5.4.6/src/lapi.c:1020
#9  0x00007ffff7fa45a4 in luaopen_ffi () from /usr/local/lib/lua/5.4/ffi.so
#10 0x000055555556432a in precallC (f=<optimised out>, nresults=1, 

Report back what you get instead.