[slang-users] configure not finding png lib

[Duke Normandin <dukeofperl@xxxxxxxxxxx>]

I want to install SLang on:

dnormandin@select-man:~/Programming/SLang/slang-2.2.4$
uname -a
Linux select-man 3.0.0-19-generic #33-Ubuntu SMP Thu Apr 19
19:05:57 UTC 2012 i686 athlon i386 GNU/Linux

`configure' ends with:

[quote]
While not required, it is recommended that you install the following
libraries and reconfigure so that the corresponding modules can be
built: png z
[/quote]

However, I have:

dnormandin@select-man:~/Programming/SLang/slang-2.2.4$
sudo apt-get install libpng12-dev zlib1g-dev libpcre3-dev
libonig-dev
 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libpcre3-dev is already the newest version.
zlib1g-dev is already the newest version.
libonig-dev is already the newest version.
libpng12-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


What have missed, please?

-- 
Duke Normandin
Turner Valley, Alberta, Canada