Re: [patch #8505] ac_cv_header_lua_h always set to yes

[Reuben Thomas]

On 14 December 2014 at 23:20, <address@hidden> wrote:

 

Whatever it means, ax_lua.m4 in some cases is broken and my goal was to improve it.

Hi,

I have worked on ax_lua.m4 and on the build system of luaposix (I wrote a lot of earlier versions of both).

If Lua distributions put their headers in subdirectory, this doesn't mean that
all source packages around that use lua in their code will follow that convention.

Source packages that use Lua have to be told where to find Lua, unless they bundle it. No problem here. (If they do not allow you to tell them where Lua is installed, they are broken.)

 

Some will even bundle lua and make things worse.

If you want to use ax_lua.m4 in a package which bundles Lua, you can set LUA_INCLUDE and other documented environment variables.

 

For portability, /usr/include, /usr/lib /usr/bin are to be always the default

and are relevant if you don't care about revisions.

With Lua, one always cares about the revision.

 

The issue can be illustrated with a real example: dev-lua/luaposix-5.1.28

That's a very out of date version (from March 2013). But maybe you're referring to building the latest version?

 

As expected, it will fail if you change AX_PROG_LUA(5.1, 5.3) to

AX_PROG_LUA(5.2, 5.3).

Since you don't seem to have Lua 5.2 installed in your example, that looks fine.

 

The issue affects lua's library and interpreter as well.

I don't see what the issue is here, or what patching luaposix has to do with issues in ax_lua.m4.

Having read the patch and bug report on savannah.org I am no wiser as to why you can't simply set the documented environment variables if you have Lua in a non-default location. I regularly build against Lua installed under my home directory, and it works fine for me (just checked again with git head) with a suitable LUA_INCLUDE setting. (If you're building lots of packages, you can set these in your build environment, no need to patch the source; Gentoo in particular has plenty of support for this sort of setting, as I'm sure you know.)

Sorry if I'm missing something, but perhaps you could explain more simply what is not working for you, starting with a bug report, i.e. "when trying to build this package, using the current ax_lua.m4, on my system, I cannot make it find my Lua libraries because…". If there is some setting that should work but doesn't, please supply a trace of a configure run that fails; if there is a path you need to set but cannot, please say what it is.

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