Torch7: Installing from luarocks fails with `torchcwrap not found`

[hughperkins]

/home/user/torch/install/bin/luajit: /tmp/luarocks_torch-scm-1-8328/torch7/random.lua:3: module 'torchcwrap' not found:
    no field package.preload['torchcwrap']
    no file '/home/user/.luarocks/share/lua/5.1/torchcwrap.lua'
    no file '/home/user/.luarocks/share/lua/5.1/torchcwrap/init.lua'
    no file '/usr/local/share/lua/5.1/torchcwrap.lua'
    no file '/home/user/git/luarocks/src/torchcwrap.lua'
    no file '/home/user/.luarocks/lib/lua/5.1/torchcwrap.so'
    no file './torchcwrap.so'
    no file '/usr/local/lib/lua/5.1/torchcwrap.so'
    no file '/usr/lib/x86_64-linux-gnu/lua/5.1/torchcwrap.so'
    no file '/usr/lib/lua/5.1/torchcwrap.so'
    no file '/usr/local/lib/lua/5.1/loadall.so'
stack traceback:
    [C]: in function 'require'
    /tmp/luarocks_torch-scm-1-8328/torch7/random.lua:3: in main chunk
    [C]: at 0x00406670
make[2]: *** [random.c] Error 1
make[1]: *** [CMakeFiles/torch.dir/all] Error 2
make: *** [all] Error 2

Seems that torchcwrap.lua is in the same directory as random.lua, but for some reason not imported ok by random.lua.

[soumith]

this is again, afaik, a false-positive.

there seems to be something really strange with your luarocks.

I just tested this, and seems to work.

How can I reproduce this on my end?

[soumith]

is this the luarocks that is shipped (sorry for asking again). And also, thanks a lot for the feedback.

[hughperkins]

Something like this:

`````` bash

!/bin/bash

build luarocks, from git:

cd $HOME
mkdir git
cd git
git clone https://github.com/keplerproject/luarocks.git

cd luarocks
./configure
make -j 4 build

echo '#!/bin/bash'>setenv.sh
echo 'PATH=$PATH:$HOME/git/luarocks/src/bin'>>setenv.sh
echo 'eval $(luarocks path --bin)'>>setenv.sh
source setenv.sh

create luarocks config file:

mkdir ~/.luarocks
echo "rocks_trees = {'/home/user/.luarocks'}">~/.luarocks/config-5.1.lua
echo "rocks_servers = {'http://luarocks.org/repositories/rocks'}">> ~/.luarocks/config-5.1.lua

cat /etc/lsb-release

DISTRIB_ID=Ubuntu

DISTRIB_RELEASE=14.04

DISTRIB_CODENAME=trusty

DISTRIB_DESCRIPTION="Ubuntu 14.04.2 LTS"```

``````

(I'm on the subway to work, and the torch install is a bit long, and I cant actually use torch whilst it's running :-P I'll try to come up with something more complete later on; feel free to just ignore this for now :-) )

[hughperkins]

I'll look at this anothre time ;-) Closing it for now.

[hughperkins]

Ok, so....

• I reinstalled luarocks, by adding --prefix /opt/luarocks to the configure, and actually doing make install and now the compile works ok :-)
• I did however need to modify my ~/torch/activate slightly, in order to be able to do require 'torch', by adding eval $(luarocks path --bin) to the end of ~/torch/activate:

#!/bin/bash

export PATH=/home/user/torch/install/bin:$PATH
export LD_LIBRARY_PATH=/home/user/torch/install/lib:$LD_LIBRARY_PATH 
export DYLD_LIBRARY_PATH=/home/user/torch/install/lib:$DYLD_LIBRARY_PATH 

eval $(luarocks path --bin)

Not sure if this is necessary/useful, or whether it's just another artefact of my eschewing installing into global system directories.

[TimZaman]

Necromancer alert. Maybe this is of use: I had exactly the same issue (user of Mac ports). Magically, using sudo ./install.sh fixed it.

[hughperkins]

nuance/caveat: using sudo for installtion is often one-way: after using it once, many intsalled files are now owned by root, and then normal, non-sudo, intsallation becomes impossible without first removing/chowning those files. (so, I would personally want to be really sure I've exhausted all avenues before going the sudo route)

[TimZaman]

I have been quite exhausted indeed after wasting a few hours on this. I'll probably send in a mac-ports PR inside install-deps, as the automagic Homebrew hurts my system. Note that mac-ports always uses sudo, whereas afaik Homebrew doesn't. I ofc do agree with your recommendation.

[hughperkins]

ah, I have dabbled with brew on linux, and found it resembled what people used to say on slashdot about gentoo: took hours/days just to do what apt-get could do in a few minutes :-P Is mac-ports more like apt-get, ie intsalls binaries, rather than building them all from scratch?

[TimZaman]

Scratch. apt-get is vastly superior. But Mac is vastly more hip.
But the scratch has advantages. f.e. if I want to install opencv with intel tbb and opencl support i just say port install opencv +tbb +ocl and it builds with tbb and opencl support.

[hughperkins]

Ok... well... ok...

I guess if you're using sudo to build everything from source in mac-ports, then using sudo to build torch from scratch kind of fits into that philosophy.

[juesato]

Leaving this here in case it's helpful to others:

sudo chmod -R 777 . from the torch git repo directory fixed this issue for me. Unclear whether this is actually any less dirty than using sudo to install.

[bill2239]

is there any solution without using sudo?

[samson-wang]

@bill2239 @juesato
Please check if you set environment variable like LUA_PATH, LUA_CPATH. I noticed that in my case and @hughperkins case, there are messages like
no file '/home/user/.luarocks/share/lua/5.1/torchcwrap.lua'.

So why check those paths? I found LUA_PATH and LUA_CPATH in my bashrc. After comment out those lines, everything works fine.

Please have a try.