[Buildroot] LuaRocks package infrastructure oddities

[Thomas Petazzoni]

Dear Ivan Sergeev,

Thanks for your feedback.

On Sun, 1 Feb 2015 20:44:34 -0800, Ivan Sergeev wrote:
> It seems that the LuaRocks package infrastructure expects to find the
> LUAFOO_ROCKSPEC file inside the LUAFOO_SUBDIR sources directory of the
> package to build it. This is a bit odd, as the rockspec is already
> downloaded or extracted from the source rock in the parent directory
> containing LUAFOO_SUBDIR, but the infrastructure relies on packages
> including that rockspec in their sources.
> 
> A condensed version of what the build appears to be doing is:
> 
> wget http://rocks.moonscript.org/lua-periphery-1.0.4-1.src.rock -O
> /path/to/buildroot/dl/ua-periphery-1.0.4-1.src.rock
> 
> cd /path/to/buildroot/output/build/ && luarocks unpack --force
> /path/to/dl/lua-periphery-1.0.4-1.src.rock
> 
> at which point is has:
>     output/build/lua-periphery-1.0.4-1/lua-periphery/  (the sources)
>     output/build/lua-periphery-1.0.4-1/lua-periphery-1.0.4-1.rockspec (the
> rockspec)
> 
> but then it descends into the sources and expects to find and build the
> rockspec file there:
> 
> cd /path/to/buildroot/output/build/lua-periphery-1.0.4-1/lua-periphery &&
> luarocks make --keep lua-periphery-1.0.4-1.rockspec
> 
> This works for me and the other LuaRocks packages currently in buildroot,
> because they happen to version the rockspec with the rest of the sources,
> but in general it seems unusual. I've attached a full log of the build.

For this part, I'll let François Perrad answer. He is the author of the
Buildroot luarocks infrastructure.

> I've also noticed that legal-info licenses are stored one extra
> subdirectory deep, at output/legal-info/licenses/luafoo/$LUAFOO_SUBDIR/,
> e.g. lua-periphery below:
> 
> $ make legal-info
> $ tree output/legal-info/licenses
> output/legal-info/licenses
> ├── am33x-cm3
> │   └── License.txt
> ├── busybox
> │   └── LICENSE
> ├── linux
> │   └── COPYING
> ├── lua
> │   └── COPYRIGHT
> ├── lua-periphery
> │   └── lua-periphery
> │       └── LICENSE
> ├── uboot
> │   └── Licenses
> │       └── gpl-2.0.txt
> └── uclibc
>     └── COPYING.LIB
> $

Yes, this is expected: we had some packages that were doing:

<pkg>_LICENSE_FILES = foo/COPYING bar/COPYING

I.e, they have two COPYING files, in two different sub-directories of
the package sources. If we were to copy all license files directly in
output/legal-info/licenses/<package-name>/, they would overwrite each
other. So instead, we replicate the hierarchy of those files inside
output/legal-info/licenses/<package-name>/.

So indeed, the fact that luarocks packages are always in a subdir means
that you have this situation for all lua packages, which gets back to
your previous question.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com