ZDoom

I think your analysis is correct. This looks like one of those edge cases where the effort for fixing it stands in no relation to the result. It's not that the player cannot receive any weapons, but that the cheat code simply does not know what weapons to give.

gzdoom -iwad doom2 -warp 1 +give weapons

The "give weapons" cheat will not work if added to the command line when starting GZDoom. Example command line:

[code]gzdoom -iwad doom2 -warp 1 +give weapons[/code]
Similarly, "give all" and "give everything" also don't work properly from the command line, since weapons is a part of what they're supposed to give. They do give everything else, though.

It seems that this happens because the player's weapon slots are initialized after these commands have already been processed. I'm not sure if this can be fixed easily, but I would still like to report it, as this behavior doesn't look consistent to me (all other cheats I can think of appear to work fine).