I know this is a work in progress, I'm only reporting this crash as a mere information, hoping that will help to polish a bit more this great mod. Sorry I couldn't help more but mapgen is far away of my programming skills :-)
This was on default minetest_game (with valleys_mapgen of course) at -95.0, 22.5, 253.0, seed: 17544283114256957415
2015-05-26 21:30:53: ERROR[main]: UNRECOVERABLE error occurred. Stopping server. Please fix the following error:
2015-05-26 21:30:53: ERROR[main]: ....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:170: bad argument #2 to 'random' (interval is empty)
2015-05-26 21:30:53: ERROR[main]: stack traceback:
2015-05-26 21:30:53: ERROR[main]: [C]: in function 'random'
2015-05-26 21:30:53: ERROR[main]: ....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:170: in function 'make_leavesblob'
2015-05-26 21:30:53: ERROR[main]: ....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:128: in function 'grow_jungle_tree'
2015-05-26 21:30:53: ERROR[main]: ...minetest/games/mapgen/mods/valleys_mapgen/mapgen.lua:322: in function '?'
2015-05-26 21:30:53: ERROR[main]: ...e/ivan/minetest-dev/bin/../builtin/game/register.lua:341: in function <...e/ivan/minetest-dev/bin/../builtin/game/register.lua:329>
In thread 7f57e897e780:
/home/ivan/minetest-dev/src/server.cpp:494: void Server::step(float): A fatal error occurred: ....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:170: bad argument #2 to 'random' (interval is empty)
stack traceback:
[C]: in function 'random'
....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:170: in function 'make_leavesblob'
....minetest/games/mapgen/mods/valleys_mapgen/trees.lua:128: in function 'grow_jungle_tree'
...minetest/games/mapgen/mods/valleys_mapgen/mapgen.lua:322: in function '?'
...e/ivan/minetest-dev/bin/../builtin/game/register.lua:341: in function <...e/ivan/minetest-dev/bin/../builtin/game/register.lua:329>
Debug stacks:
DEBUG STACK FOR THREAD 7f57e119a700:
#0 virtual void* EmergeThread::Thread()
(Leftover data: #1 virtual MapBlock* ServerMap::emergeBlock(v3s16, bool): p=(-7,3,18), create_blank=0)
(Leftover data: #2 ServerMapSector* ServerMap::createSector(v2s16): p2d=(-9,18))
DEBUG STACK FOR THREAD 7f57e199b700:
#0 virtual void* ServerThread::Thread()
#1 void Server::Receive()
(Leftover data: #2 void Server::SendBlocks(float))
(Leftover data: #3 void Server::SendBlockNoLock(irr::u16, MapBlock_, irr::u8, irr::u16))
(Leftover data: #4 void ItemStack::serialize(std::ostream&) const)
(Leftover data: #5 bool getCraftingResult(Inventory_, ItemStack&, bool, IGameDef*))
DEBUG STACK FOR THREAD 7f57e897e780:
#0 int main(int, char**)
#1 Dedicated server branch
#2 void dedicated_server_loop(Server&, bool&)
#3 void Server::step(float)
./mapgen.sh: line 1: 3119 Avortat ~/minetest-dev/bin/minetest --server --config /home/ivan/.minetest/games/mapgen/minetest.conf --worldname world --gameid mapgen