Yes, triggers.qc is in progs.src. It's compiled. I renamed it to xxx_triggers_allplayers and then opened the compiled progs.dat and found the new name inside.

The source code for the function:

void() trigger_allplayers =
{
InitTrigger();
self.think = trigger_allplayers_think;
self.nextthink = time + 0.5;
}; 

Is it possible that quake isn’t loading the progs.dat you expect? For example, a progs.dat ouside a pak file won’t override a progs.dat inside a pak file in the same mod folder. 

Are you sure the map is being launched with your mod being selected via -game your_mod_name? Can you make some other change in the mod that will be really obvious, like setting starting health to 200?

If the command line for the mod is correct but the mod still isn't loading, run the checklist to be sure is that your progs.dat file is being used. Make sure that it's in the root directory of your mod, and that there are no .pak files in the mod directory which also have progs.dat in them (files in a pak will take priority over unpacked files). 

 

Well, the fact that it shows this error about "trigger_allpalyers" tells me it's loading my progs.dat but I can trying changing something else too.

I'm putting it in id1\, inside a progs.pak file and I run with the Ironwail engine (but I believe progs.dat should be supported by literally every Quake port). 

That error message actually tells you the opposite of what you think it does. It tells you about something your MAP contains. The error means the mod you are running does not contain trigger_allplayers - which is probably because you are running the vanilla quake mod and not your custom one.

I would recommend creating a new mod folder under quake called "allplayers", put the progs.dat file in that folder, then run Ironwail with the -game allplayers command line switch. That should ensure you are actually running your custom mod. 

Ah, yes, good point.