Problem with QMAKESPEC

I have to compile project to 32-bit platform on OpenSuse 11.4 x86_64.
I set qmake options: -r -spec linux-g++-32.
Compiler is linking libs rom /usr/lib64 instead of /usr/lib returning errors:

Code:

---

g++ -m32 -o test-32 main.o mainwindow.o moc_mainwindow.o    -L/usr/lib64 -lQtSql -L/usr/lib64 -lQtGui -L/usr/X11R6/lib64 -lQtCore -lpthread 
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtSql.so when searching for -lQtSql
make: Opuszczenie katalogu `/home/neon/workspace/qt4/test-32-build-desktop'
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtSql.so when searching for -lQtSql
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/4.5/../../../libQtSql.so when searching for -lQtSql
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtSql.so when searching for -lQtSql
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: cannot find -lQtSql
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/4.5/../../../libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: cannot find -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtCore.so when searching for -lQtCore
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtCore.so when searching for -lQtCore
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/4.5/../../../libQtCore.so when searching for -lQtCore
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libQtCore.so when searching for -lQtCore
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: cannot find -lQtCore
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libpthread.so when searching for -lpthread
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libpthread.a when searching for -lpthread
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libpthread.so when searching for -lpthread
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/libpthread.a when searching for -lpthread

---

I have installed 32-bit qt4 libs. How to build 32-bit app on 64-bit system?

PS: On second computer with fedora everything is working correct.

I'm not familiar with using qmake options to accomplish this. I've always set the QMAKESPEC environment variable to whatever spec I wanted - in this case, I'd set it to 'linux-g++-32'. Try that and see if it makes a difference.

I had remove qmake option and set QMAKESPEC and with simple test app it works.
When I'm linking external library, compiled for i386 architecture, I'm getting error:

Code:

---

:: error: i386 architecture of input file `/home/path to lib/libdr.a(libdr.o)' is incompatible with i386:x86-64 output

---

Do a 'make clean' on your project; you probably have some previously compiled 64-bit object files in it.

I made "make clean". Did not help. :(

Hi, sorry to resurrect such an old post, but I just encountered the very same problem: forcing a 32-bit compilation on a 64-bit machine using -spec linux-g++-32 still uses /usr/lib64 as main library linking path, instead of /usr/lib, which leads to linking problems. I guess it's a bug in spec files or something, and which maybe has been yet solved as the machine I experienced this had a fairly old setup (qmake 4.3.4).

Anyway, for sake of documentation and just in case anyone else stumbles over the same problem, I found a possible workaround, which is adding also QMAKE_LIBDIR=/usr/lib parameter to qmake command line. Although this doesn't remove /usr/lib64 from linking path, at least /usr/lib is inserted BEFORE it, so linker finds first the 32 bit libraries and uses them.

Kind regards.

If you use the 32-bit qmake from your 32-bit build of Qt then you should get a 32-bit result by default. Are you getting this result using the 32-bit qmake?