Unable to compile under debian squeeze / Something Wrong about webp HOT 9 CLOSED

Interesting. I had no problem compiling it using sid. I managed somehow to 
build liblept without any copy (just go into src, and run make. DO NOT USE 
./configure).

Anyway strange error.

Yes, I experienced this compiling it on AmigaOS 4.1 too. The solution for me 
was to add webpio.c and webpiostub.c to the Makefile in src/, as well as 
setting #define HAVE_LIBWEBP 1 in config_auto.h

After rebuilding the library, and manually moving it to the "nodebug" folder, 
the problem was solved.

I have exactly the same problem under OpenSuse 11.2

Can you give a try with the latest version 0.0.4

Can you try following steps with version 0.0.4 source tar:

untar  0.0.4 source files

1.) cd webp/leptonlib-1.066;

2.) ./configure && make clean && make && sudo make install;

3.) ls -al /usr/local/include/liblept/leptprotos.h; // Verify the date-time 
stamp of this header include file.

4.) ls -alt /usr/local/lib/liblept.a;  // Verify the date-time stamp of newly 
created liblept.a

5.) grep pixWriteWebPwithTargetPSNR /usr/local/include/liblept/leptprotos.h; // 
Verify that this patched leptonica source code (header) have the necessary 
functions required for webpconv.

6.) strings /usr/local/lib/liblept.a | grep pixWriteWebPwithTargetPSNR; // 
Verify that this patched version of liblept.a have the necessary functions 
required for webpconv

7.) cd ../libwebp;

8.) ./configure && make clean && make && sudo make install;

Verify that following command was used to link 'webpconv' binary:
g++ -Werror -Wall -O2 -g -O2 -L/usr/X11R6/lib -L/usr/local/lib  -o webpconv 
webpimg.o webpconv.o -llept -ljpeg -lpng -lz -lm -lvpx -lpthread -lvpx

Try with the latest version.
Closing this. Will reopen once get any update from requester.