LMDBProvider has threads issues

[ltrottier]

Hi,

Thank for your code, it really accelerated my experimentations. I am currently using a system wide installation of torch on a remote server. I have create the lmdb datasets, but when this line gets executed in Main.lua

data.ValDB:threads()

I get the following error

FATAL THREAD PANIC: (read) ...5990b6357_gcc4.8_cuda7.5.18/share/lua/5.1/torch/File.lua:343: unknown Torch class <lmdb.env>

It seems that the threads in LMDBProvider does not know what lmdb.env is. It is worth noting that cacheSeq and cacheRand are working fine.

Do you know what could be the cause ?