I really don't have any idea how to fix this issue. I try to compile like so:
:~/docs/xxdiff-3.2/src$ make -f Makefile.bootstrap makefile
/usr/lib/qt/bin/qmake -o Makefile.qmake xxdiff.pro
cat Makefile.qmake Makefile.extra > Makefile
:~/docs/xxdiff-3.2/src$ make -j3
/usr/lib/qt/bin/uic markersWidgetBase.ui -o markersWidgetBase.h
/usr/lib/qt/bin/uic optionsDialogBase.ui -o optionsDialogBase.h
/usr/lib/qt/bin/uic searchDialogBase.ui -o searchDialogBase.h
bison -d -o y.tab.c -p resParser -b resParser resParser.y
g++ -c -pipe -DXX_DEBUG -Wall -W -g -D_REENTRANT -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_NO_DEBUG -I/usr/lib/qt/mkspecs/default -I. -I/usr/lib/qt/include -o suicideMessageBox.o suicideMessageBox.cpp
g++ -c -pipe -DXX_DEBUG -Wall -W -g -D_REENTRANT -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_NO_DEBUG -I/usr/lib/qt/mkspecs/default -I. -I/usr/lib/qt/include -o main.o main.cpp
rm -f resParser_yacc.cpp resParser_yacc.h
mv -f y.tab.h resParser_yacc.h
mv -f y.tab.c resParser_yacc.cpp
g++ -c -pipe -DXX_DEBUG -Wall -W -g -D_REENTRANT -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_NO_DEBUG -I/usr/lib/qt/mkspecs/default -I. -I/usr/lib/qt/include -o overview.o overview.cpp
In file included from ./resources.h:651,
from ./line.h:39,
from ./app.h:35,
from main.cpp:29:
./resources.inline.h: In member function 'int* XxResources::getDynProgTable(uint, uint) const':
./resources.inline.h:266: error: 'realloc' was not declared in this scope
main.cpp: In function 'int main(int, char**, char**)':
main.cpp:62: error: 'putenv' was not declared in this scope
make: *** [main.o] Error 1
make: *** Waiting for unfinished jobs....
In file included from ./resources.h:651,
from ./line.h:39,
from ./app.h:35,
from overview.cpp:28:
./resources.inline.h: In member function 'int* XxResources::getDynProgTable(uint, uint) const':
./resources.inline.h:266: error: 'realloc' was not declared in this scope
make: *** [overview.o] Error 1
Adding #include <malloc.h> to src/resources.inline.h works around this problem.