[Solved] Building 32-bit app under 64-bit Ubuntu - Cannot find -lGL ( OpenGL) even though added to lib path ?

EdOfTheMountain

I have both 32 and 64 bit Qt 5.3.1 installed under Ubuntu 64-bit.
I can build a 64-bit Qt app no problems
I installed 32-bit mesa and many other dependencies in order to install 32-bit Qt
I added "-m32" and GL lib path to qmake project file
32-bit Qt apps compile but cannot link with GL
The following link error occurs when building for Desktop Qt 5.3 GCC 32bit:
@
/usr/bin/ld: cannot find -lGL
@

Is this a lib path order problem? What am I not seeing?

File: Qt Project
@
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = trash-widget
TEMPLATE = app

Ubuntu x64: x86_64

message(QMAKE_HOST.arch = $$QMAKE_HOST.arch)

GCC 32-bi: i386

GCC 64-bit: x86_64

message(QT_ARCH = $${QT_ARCH})

equals(QT_ARCH, "i386") {
TARGET = $${TARGET}x32
QMAKE_CXXFLAGS += -m32

# GL was installed here:
# /usr/lib/i386-linux-gnu/mesa/libGL.so.1.2.0
LIBS += -L/usr/lib/i386-linux-gnu/mesa

} equals(QT_ARCH, "x86_64") {
TARGET = $${TARGET}x64
}

SOURCES += main.cpp
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
@

Compiler Output: "/usr/bin/ld: cannot find -lGL"
@
g++ -m32 -Wl,-rpath,/opt/Qt5.3.1-x32/5.3/gcc -Wl,-rpath,/opt/Qt5.3.1-x32/5.3/gcc/lib -o trash-widgetx32 main.o mainwindow.o moc_mainwindow.o -L/usr/lib/i386-linux-gnu/mesa -L/opt/Qt5.3.1-x32/5.3/gcc/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread
/usr/bin/ld: cannot find -lGL
collect2: error: ld returned 1 exit status
make: *** [trash-widgetx32] Error 1
14:25:03: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project trash-widget (kit: Desktop Qt 5.3 GCC 32bit)
When executing step 'Make'
14:25:03: Elapsed time: 00:03.
@

Thanks in advance,

-Ed

SGaist

Hi,

Did you install the OpenGL dev package ?

EdOfTheMountain

Thank you! That was it. I can now build either 32 or 64 bit Qt apps.

I installed these two packages. I am not sure if I needed mesa-common-dev but once I installed libglu1-mesa-dev:i386 all was good!
@
sudo apt-get install mesa-common-dev:i386
sudo apt-get install libglu1-mesa-dev:i386
@

I had them in my development environment notes but somehow missed installing. I need to make a script or a kickstart.

Thanks again,

-Ed

EdOfTheMountain

Under Ubuntu 14.04 64-bit,

I added these packages in order to install Qt 5.3.1 32-bit and build 32-bit apps under 64-bit Ubuntu.

@
sudo apt-get install \

Qt: deps \

libsm6:i386
libxrender1:i386
libfontconfig1:i386
libxext6:i386
libgtk2.0-0:i386
libcanberra-gtk-module:i386
libxslt1.1:i386
libglu1-mesa-dev:i386
libc6-i386
libglib2.0-0:i386
libsm6:i386
libglu1-mesa:i386
libgl1-mesa-glx:i386
libxext6:i386
libxrender1:i386
libx11-6:i386
libfontconfig1:i386
lsb-core
g++-multilib \

Qt Creator Deps: \

libgstreamer0.10-0:i386
libgstreamer-plugins-base0.10-0:i386

Install 32-bit Qt:
chmod +x qt-opensource-linux-x86-android-5.3.1.run
./qt-opensource-linux-x86-android-5.3.1.run
@

I used sudo to run the Qt installers and installed each Qt to it's own folder:

/opt/Qt5.3.1-x32
/opt/Qt5.3.1-x64

Then I launched 64-bit Qt Creator and configures a 32 bit Qt version, then cloned the 64-bit build kit and renamed it to 32-bit and made it point to the 32bit Qt version.

I suspect there may be better solutions to install 32 and 64 bit Qt that do not use as much disk space but this approach works and does not make my brain hurt too much. ;-)

-Ed

EdOfTheMountain

Apparently OpenGL 32 and 64 bit packages remove and replace each other under 64-bit Ubuntu and last package installed wins.