Today I ran into a small problem. I needed to parse some files with Lua data (not my choice!) into a database (generic, but think MySQL). Of course I probably could have done this using Lua directly but I didn’t want to spend more time on this than necessary so I went with what I’m most comfortable with; perl.
A quick look at CPAN and I found Data::Lua which should parse my Lua data quickly. Turning to my development system running Debian I quickly installed Lua and went to (locally, for my private user) install Inline::Lua and Data::Lua. That should do the trick. Except that I ran into 2 problem with the Data::Lua tests:
t/parse-file.t …… 1/8 error: [string "_INLINED_LUA"]:18: attempt to call a nil value (global 'setfenv')
and
t/parse.t ……….. 1/7 error: [string "_INLINED_LUA"]:3: attempt to call a nil value (global 'loadstring')
After examining this further I found out that these functions setfenv and loadstring was removed from Lua in version 5.2. My Debian system has version 5.3 (or was it 5.4?) installed as default.
Solution
To make this work I had to remove the default Lua version that was installed and replace it with and older 5.1.
# apt-get remove lua5.3 liblua5.3-dev # apt-get install liblua5.1-0-dev lua5.1
Then I had to (force) rebuild Inline::Lua since it was built against the 5.3 libraries
$ cpan -f install Inline::Lua
After this Data::Lua passed all tests with no problems and installed smoothly. It remains to see if it solves my Lua data into a database via perl exercise.
Examining Data::Lua a bit
Looking into the single file that is Data::Lua it seems that adjusting the two available functions to for with modern Lua versions is a really easy fix. But from what I can make out it seems like that module is more or less abandoned by its’ author. Last update was in 2009 and it is version 0.02. I also see that my problem is reported as a bug over 2 years ago so I guess it is not getting any attention. Sad.