I've been running slackware64-current since the beta 1 was announced and I get a lot of build error like this one:
Is It a commun behaviour for a beta release ?
Since It' the first time that I run slackware-current, I'm asking you.

Most of the time (but not all the time...unfortunately) the fix is trivial. I export in the shell or I add the missing library to the Makefile, but It happens so often that It's getting on my nerves actually.

I read in on the mailing list for trinitydesktop that gcc-4.7 broke quite a bit of their code.
Are those linker troubles related to gcc itself ?
If so, I don't mind downgrading gcc, anyhow gcc-4.6.3 is running fine on current.

Is it due to binutils ?

I wonder where the proble lies, because I've been using Slackware fulltime since slackware64-13.0, and I never ran against such impediments before.
Usually compiling programs on Slackware is a play game.

I run the 32 bit version so I can't help that much, but I would first make sure that your your slackware64-current be fully and properly updated with the usual sequence:

slackpkg update
slackpkg install-new
slackpkg upgrade-all
slackpkg clean-system

with of course a proper mirror uncommented in /etc/slackpkg/mirrors and all .new files taken care of.

But I guess you did check that already

And maybe you could give an example of a program that someone can try to compile & link on his/her system to see if he/she gets the same results.

Well actually I didn't upgrade from 13.37, I made a fresh install with an iso taken from ftp.slackware.no.

I don't have kde installed at the moment otherwise all the libraries, including the new ones are installed. I don't think a missing prog is involved in here.

The code error I gave for instance comes from Juce, the c++ gui library.
I order to compile Juce, I not only added -ldl to the makefile but -lXext as well.
Afterwards, everything compiled fine.

If I'm the only one who experience these troubles, that mean that my install is corrupted, otherwise something goes wrong with the toolchain.

I think nothing is going wrong, it's the new ld that needs those LDFLAGS because indirect linking isn't allowed anymore: many apps used it and they haven't been fixed yet, so the build scripts must be patched.
See here

http://fedoraproject.org/wiki/Unders...gDSOLinkChange

There is a (theoretical) possibility that the iso be corrupted or non complete then.

If you don't get a more valuable answer in some time I would try with another iso then.

Or you could keep a local mirror of -current, use an USB installer and (re) install the packages from your local mirror.

Or run "slackpkg install slackware" and see what it shows, beside KDE packages.

EDIT Sorry to be late, I guess that ponce's answer is a better one.

ponce eventually gave the answer.
The link from Fedora is quite clear on the topic.

Ponce, Didier thank you, both, for your help and from my part, sorry for the noise !