在ubuntu 12.04上无法在qt调试模式下显示变量值

Question

I've installed qt 5.2 on ubuntu 12.04. but when I run it in the debug mode variables do not appear in locals and expressions window. I tried right-clicking on the variable and clicking on add expression evaluator but nothing happens. I also tried dragging it to locals and expressions window but instead of its value it puts in value column and the type column is left empty.

Only for global variables qt shows the correct values.

I tried the same version of qt on a 13.10 ubuntu and it works fine. Can anyone tell me what I should do to fix this?

EDIT:

This is the compile output

17:10:23: Running steps for project test1...

17:10:23: Configuration unchanged, skipping qmake step.

17:10:23: Starting: "/usr/bin/make" 

g++ -c -pipe -g -std=c++0x -Wall -W -D_REENTRANT -fPIE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_CORE_LIB -I/opt/Qt5.2.0/5.2.0/gcc/mkspecs/linux-g++ -I../test1 -I/opt/Qt5.2.0/5.2.0/gcc/include -I/opt/Qt5.2.0/5.2.0/gcc/include/QtCore -I. -I. -o main.o ../test1/main.cpp

g++ -Wl,-rpath,/opt/Qt5.2.0/5.2.0/gcc -Wl,-rpath,/opt/Qt5.2.0/5.2.0/gcc/lib -o test1 main.o   -L/opt/Qt5.2.0/5.2.0/gcc/lib -lQt5Core -lpthread 
{ test -n "" && DESTDIR="" || DESTDIR=.; } && test $(gdb --version | sed -e 's,[^0-9][^0-9]*\([0-9]\)\.\([0-9]\).*,\1\2,;q') -gt 72 && gdb --nx --batch --quiet -ex 'set confirm off' -ex "save gdb-index $DESTDIR" -ex quit 'test1' && test -f test1.gdb-index && objcopy --add-section '.gdb_index=test1.gdb-index' --set-section-flags '.gdb_index=readonly' 'test1' 'test1' && rm -f test1.gdb-index || true

17:10:24: The process "/usr/bin/make" exited normally.

17:10:24: Elapsed time: 00:01.

EDIT:

For anyone who faces the same problem, Just as Nejat said I installed gdb 7.6 which fixed it.

Answer 1

The problem is that gcc 4.8 is using a newer format for storing debugging information and you are using gdb version less than 7.5. You can check your gdb version by:

gdb --version

You should upgrade your gdb to the newest version.

The same symptom can result from having a gdb that is too new, instead of too old.