biomemap is nil on generating caverealm (subterrane fork) with mg

[Poikilos]

I am using experimental mapgen (mg). I'm not sure if this is an mg issue, caverealms issue, or subterrane issue--I looked at the line in question, which uses biomemap, a local variable which should contain the result of minetest.get_mapgen_object("biomemap"). I don't know enough to know why get_mapgen_object would ever return nil after looking up its meaning. If I restart the server, it works for a while, but when trying to dig deeper in a certain location the server crashes. Apparently the problem happens when a caverealm generates.

Seed: BagEnd
Location: /teleport 17,-566,98 (then start digging down)
MapGen: v7
minetest version: 0.5.0-dev (~2018-02-21)
mapgen mods:

• mg
• subterrane
• caverealms (FaceDeer's fork of caverealms which is integrated with mapgen v7's perlin noise and uses subterrane)
• magma_conduits
• minor mapgen mods: moreores, techic, ... for others see https://github.com/expertmm/EnlivenMinetest/blob/master/etc/game-install-ENLIVEN

2018-02-23 19:37:29: ACTION[Main]: [playereffects] Server shuts down. Rescuing data into playereffects.mt
2018-02-23 19:37:29: ACTION[Main]: [playereffects] Wrote playereffects data into /home/owner/.minetest/worlds/FCAWorldB/playereffects.mt.
2018-02-23 19:37:30: ACTION[Main]: [fishing] Server shuts down. saving trophies table
2018-02-23 19:37:31: ERROR[Main]: ServerError: AsyncErr: Lua: finishGenRuntime error from mod 'caverealms' in callback environment_OnGenerated(): ...al/share/minetest/games/ENLIVEN/mods/subterrane/init.lua:181: attempt to index local 'biomemap' (a nil value)
2018-02-23 19:37:31: ERROR[Main]: stack traceback:
2018-02-23 19:37:31: ERROR[Main]: ...al/share/minetest/games/ENLIVEN/mods/subterrane/init.lua:181: in function <...al/share/minetest/games/ENLIVEN/mods/subterrane/init.lua:116>
2018-02-23 19:37:31: ERROR[Main]: /usr/local/share/minetest/builtin/game/register.lua:420: in function </usr/local/share/minetest/builtin/game/register.lua:400>

[Poikilos]

I moved this issue to minetest-mods/mg#12 but feel free to reopen this if I'm wrong.

[Poikilos]

@Ekdohibs says at minetest-mods/mg#12:

I think the issue is with caverealm, since I think biomemap is not defined if the mapgen used does not support it. Since mg uses the "singlenode" mapgen, biomemap is not supported in it.