Compile Output failed: cannot find -lpthread

JonB

@malamerda
I cannot see the -lm on that line, I guess it's earlier on than you show. I cannot see anything obviously wrong with the syntax, so maybe the cannot find -lpthread does indicate it can't find the libpthread.a (or could it be libpthread.so, not sure). Do you have that file anywhere in the arm-linux-gnueabihf hierarchy, or elsewhere but for cross-compile? Use find or locate to search for you (e.g. locate pthread).

malamerda

this is what I found with locale libpthread:

JonB

@malamerda
Well I think that looks right, assuming it looks there.
I don't suppose you can find/paste the whole of your link line, by whatever means, what you showed earlier is only the end of it, I#d like to see the whole thing from the start (before what you show beginning with .._appTerm)?
After that, if say you temporarily cp or ln -s both the libpthread.a & libpthread.so into the compiler object/executable directory for your project (where the `.o files are), does that alter the error message? (Don't forget to delete these copies/soft links from the directory you put them in when done.)

malamerda

this the main.pro building output:
12:52:15: Running steps for project InterCIC...
12:52:15: Configuration unchanged, skipping qmake step.
12:52:15: Starting: "/usr/bin/make" -j3
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/arm-linux-gnueabihf-g++ -mfloat-abi=hard --sysroot=/opt/rpi-qt5.12.6/sysroot/ -Wl,-O1 -s -Wl,-rpath,/usr/local/qt5.12.6/lib -Wl,-rpath-link,/opt/rpi-qt5.12.6/qt5.12.6/lib -Wl,-rpath-link,/opt/rpi-qt5.12.6/sysroot/opt/vc/lib -Wl,-rpath-link,/opt/rpi-qt5.12.6/sysroot/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link,/opt/rpi-qt5.12.6/sysroot/lib/arm-linux-gnueabihf -o ../bin/interCIC main.o qrc___InterCIC_Resources_Qml_Widgets_Widgets_qmlcache.o qrc___InterCIC_Resources_Qml_Singleton_Singleton_qmlcache.o qrc_Imagenes.o qrc_Sonidos.o qrc_translations.o qrc___InterCIC_appAspi_Resources_Qml_MainAspi_mainAspi_qmlcache.o .._Resources_Qml_Widgets_CustomProgressBar_qml.o .._Resources_Qml_Widgets_VirtualKeyboard_qml.o .._Resources_Qml_Widgets_WeatherWidget_qml.o .._Resources_Qml_Widgets_CustomText_qml.o .._Resources_Qml_Widgets_CustomTextField_qml.o .._Resources_Qml_Widgets_CustomComboBox_qml.o .._Resources_Qml_Widgets_CustomButton_qml.o .._Resources_Qml_Widgets_VirtualKeyboardPanel_qml.o .._Resources_Qml_Widgets_ImageSvg_qml.o .._Resources_Qml_Widgets_CustomTextMoving_qml.o .._Resources_Qml_Widgets_LangButton_qml.o .._Resources_Qml_Complementos_AsistenteLavado_qml.o .._Resources_Qml_Complementos_BotonConf_qml.o .._Resources_Qml_Complementos_BotonIstobal_qml.o .._Resources_Qml_Complementos_FondoPantalla_qml.o .._Resources_Qml_Complementos_C_NumeroPrograma_qml.o .._Resources_Qml_Complementos_BotonSelecFase_qml.o .._Resources_Qml_Complementos_BotonX_qml.o .._Resources_Qml_Complementos_PMR_qml.o .._Resources_Qml_Complementos_LogoIstobal_qml.o .._Resources_Qml_Complementos_TiempoDinero_qml.o .._Resources_Qml_Complementos_QMLError_qml.o .._Resources_Qml_Complementos_A_InfoServicios_qml.o .._Resources_Qml_Complementos_C_InfoServicios_qml.o .._Resources_Qml_Complementos_TiempoDinero_15p_qml.o .._Resources_Qml_Ventanas_InstrucTFidelidadWin_qml.o .._Resources_Qml_Ventanas_C_InstrucPistolaWin_qml.o .._Resources_Qml_Ventanas_TFidelidadAceptadaWin_qml.o .._Resources_Qml_Ventanas_ConfirmFinWin_qml.o .._Resources_Qml_Ventanas_CreditoAPagarWin1_qml.o .._Resources_Qml_Ventanas_C_PagoTiempoSelWin_qml.o .._Resources_Qml_Ventanas_RecargaTFidMonedas_qml.o .._Resources_Qml_Ventanas_InfoFinServicio_qml.o .._Resources_Qml_Ventanas_ImportPersWin_qml.o .._Resources_Qml_Ventanas_ErrorCodigoWin_qml.o .._Resources_Qml_Ventanas_InstrucTarjetaWin_qml.o .._Resources_Qml_Ventanas_C_PagoTiempoSelWin_15p_qml.o .._Resources_Qml_Ventanas_ErrorCriticoWin_qml.o .._Resources_Qml_Ventanas_PagoTiempoSelWin_qml.o .._Resources_Qml_Ventanas_MetodosPagoWin_qml.o .._Resources_Qml_Ventanas_ModoEsperaWin_qml.o .._Resources_Qml_Ventanas_PagoAceptadoWin_qml.o .._Resources_Qml_Ventanas_TFidelidadWin_qml.o .._Resources_Qml_Ventanas_C_ModoEsperaWin_qml.o .._Resources_Qml_Ventanas_ErrorPagoWin_qml.o .._Resources_Qml_Ventanas_C_TFidelidadWin_qml.o .._Resources_Qml_Ventanas_BienvenidaWin_qml.o .._Resources_Qml_Ventanas_RecargaTFidTarjetaWin_qml.o .._Resources_Qml_Ventanas_RecargaTFidelidadWin_qml.o .._Resources_Qml_Ventanas_CreditoAPagarWin_qml.o .._Resources_Qml_Ventanas_IntroCodigo_qml.o .._Resources_Qml_Ventanas_InstrucMoneda_qml.o .._Resources_Qml_Utils_models_js.o .._Resources_Qml_Utils_utils_js.o .._Resources_Qml_Utils_JSON_JSONListModel_qml.o .._Resources_Qml_Utils_JSON_jsonpath_js.o .._Resources_Qml_Utils_JSON_JSONQueue_qml.o .._Resources_Qml_Utils_JSON_JSONpost_js.o .._Resources_Qml_Conf_ConfUpgrades_qml.o .._Resources_Qml_Conf_ConfLogin_qml.o .._Resources_Qml_Conf_ConfContFunc_qml.o .._Resources_Qml_Conf_QMLConfiguracion_qml.o .._Resources_Qml_Conf_ConfSignalbConfPLC_qml.o .._Resources_Qml_Conf_ConfAspirador_qml.o .._Resources_Qml_Conf_ModeloListaConf_qml.o .._Resources_Qml_Conf_ConfPlcS7_qml.o .._Resources_Qml_Conf_ConfLogger_qml.o .._Resources_Qml_Conf_ConfBusiness_qml.o .._Resources_Qml_Conf_ConfAvanzadas_qml.o .._Resources_Qml_Conf_ConfBotonCancel_qml.o .._Resources_Qml_Conf_ConfImportes_qml.o .._Resources_Qml_Conf_ConfFail_qml.o .._Resources_Qml_Conf_ConfReinicio_qml.o .._Resources_Qml_Conf_ConfCentro_qml.o .._Resources_Qml_Conf_ConfUpgradesFrom.ui_qml.o .._Resources_Qml_Conf_ConfManager_qml.o .._Resources_Qml_Conf_ConfRed_qml.o .._Resources_Qml_Conf_ConfContEco_qml.o .._Resources_Qml_Conf_ConfPlcCondicional_qml.o .._Resources_Qml_Conf_ConfBotonAceptar_qml.o .._Resources_Qml_Conf_ConfPagos_qml.o .._Resources_Qml_Conf_ConfLangs_qml.o .._Resources_Qml_Conf_ConfSistema_qml.o .._Resources_Qml_Conf_ConfTarifas_qml.o .._Resources_Qml_Test_TestBotones_qml.o .._Resources_Qml_Test_TestCoiner_qml.o .._Resources_Qml_Test_TestInOut_qml.o .._Resources_Qml_Test_TestMifare_qml.o .._Resources_Qml_Test_TestTeclado_qml.o .._Resources_Qml_Test_TestInOutCustomRow_qml.o .._Resources_Qml_Test_TestCanMonitor_qml.o .._Resources_Qml_Test_TestQR_qml.o .._Resources_Qml_Test_TestTPV_qml.o .._Resources_Qml_Singleton_Languages_qml.o .._Resources_Qml_Singleton_VariablesGlobales_qml.o .._appAspi_Resources_Qml_MainAspi_mainAspi_qml.o .._appAspi_Resources_Qml_TestAspi_TestAspi_qml.o .._appCentro_Resources_Qml_MainCentro_mainCentro_qml.o .._appCentro_Resources_Qml_TestCentro_TestCentro_qml.o .._appTerm_Resources_Qml_MainTerm_mainTerm_qml.o .._appTerm_Resources_Qml_TestTerm_TestTerm_qml.o qmlcache_loader.o -L/opt/rpi-qt5.12.6/sysroot//opt/vc/lib -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../appAspi/ -lappAspi -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../appCentro/ -lappCentro -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../appTerm/ -lappTerm -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../idilibs/ -lidilibs -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../libs/ -llibs -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../selbalibs/ -lselbalibs -L/home/disco_ssd/otilio/Qt_projects/CIC/build-InterCIC-CM4_Rasp_Qt5_12_6-Release/main/../snap7/ -lsnap7 /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5QuickControls2.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Quick.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Svg.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5PrintSupport.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Widgets.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Multimedia.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Gui.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Qml.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Network.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5SerialPort.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5SerialBus.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Sql.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Core.so /opt/rpi-qt5.12.6/sysroot//usr/lib/arm-linux-gnueabihf/libGLESv2.so -lpthread
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: cannot find -lpthread
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: cannot find -lm
collect2: error: ld returned 1 exit status
make: *** [Makefile:461: ../bin/interCIC] Error 1
12:52:15: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project InterCIC (kit: CM4_Rasp_Qt5.12.6)
When executing step "Make"
12:52:15: Elapsed time: 00:00.

I've done a ln -s from the dir where the files appear to /opt/rpi-qt5.12.6/sysroot/usr/lib/arm-linux-gnueabihf but this not fixe the issue. I'll try to do other ln -s to the executable pro.
Really thanks

malamerda

I did the ln -s of libpthread* and libm* to object/executable/lib dir and the message have changed asking for another libs:

rpi-qt5.12.6/qt5.12.6/lib/libQt5Quick.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Svg.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5PrintSupport.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Widgets.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Multimedia.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Gui.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Qml.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Network.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5SerialPort.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5SerialBus.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Sql.so /opt/rpi-qt5.12.6/qt5.12.6/lib/libQt5Core.so /opt/rpi-qt5.12.6/sysroot//usr/lib/arm-linux-gnueabihf/libGLESv2.so -lpthread
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: cannot find /lib/libc.so.6
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: cannot find /usr/lib/libc_nonshared.a
/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: cannot find /lib/ld-linux-armhf.so.3
collect2: error: ld returned 1 exit status
make: *** [Makefile:461: ../bin/interCIC] Error 1
13:01:09: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project InterCIC (kit: CM4_Rasp_Qt5.12.6)
When executing step "Make"
13:01:09: Elapsed time: 00:01.

I can't understand what happend with the libs dependencies in the project and I don't know how and where I can changed them.

JonB

@malamerda
Still looks kind of Ok to me.
Mysteriously, there is still no -lm argument anywhere, so where/why it gets its cannot find -lm I do not know.
My "copy/link" was never intended to "fix" the issue, just to see if changed the error message. Though I'm not even sure lib... files in the current directory are picked up by -l... argument.

JonB

@malamerda said in Compile Output failed: cannot find -lpthread:

I did the ln -s of libpthread* and libm* to object/executable/lib dir and the message have changed asking for another libs:

Ah, the clue I hoped for! That tells you the ld is not currently being told to look for libraries in some directory where it is searching (usually the ones named in all your -L... arguments [note: upper-case L for this]). I know nothing about RPi/cross-compilation, but that is what you need to investigate.....

malamerda

this is the ./configure I used to cross compile the raspberry sysroot:

../qt-everywhere-src-5.12.6/configure -opengl es2 -eglfs -no-gtk -device linux-rasp-pi-g++ -device-option CROSS_COMPILE=/opt/rpi-qt5.12.6/tools/cross-pi-gcc-8.3.0-1/bin/arm-linux-gnueabihf- -sysroot /opt/rpi-qt5.12.6/sysroot/ -prefix /usr/local/qt5.12.6 -extprefix /opt/rpi-qt5.12.6/qt5.12.6 -opensource -confirm-license -release -reduce-exports -force-pkg-config -nomake examples -nomake tests -no-compile-examples -no-use-gold-linker -skip qtwayland -skip qtwebengine -skip qtlocation -skip qtsensors -qt-pcre -no-pch -evdev -system-freetype -fontconfig -glib -qpa eglfs -v -recheck -L/opt/rpi-qt5.12.6/sysroot/usr/lib/arm-linux-gnueabihf -I/opt/rpi-qt5.12.6/sysroot/usr/include/arm-linux-gnueabihf

I'm not sure if I have to change the path in the -L/opt/... because I'm not sure the relation between this path and the Qt creator to build a project.

Really thanks for your time.

malamerda

@JonB
anyway, do you know the way to install a Qt5.12.6 in embedded system in wich is installed by default a Qt5.11.3 version.
Our goal is to get a raspberry with a buster (raspbian distribution) with a Qt5.12.6 version. To do this I downloaded the qt5.12.6 sources and try to configure, make and make install in order to prepare a sysroot to cross compiling with a ubuntu 20.04 host.

Jakub777

Hello guys I had similiar issue and I got some solution. In my case I was trying to make a crosscompilation between my VM with ubuntu 20 and RPI with ubuntu server 20. I was using this guide https://github.com/abhiTronix/raspberry-pi-cross-compilers/blob/master/QT_build_instructions.md
For some weird reason when there is line in qmake:
QT -= gui
it removes -L/home/jakub/rpi-qt/sysroot/usr/lib/arm-linux-gnueabihf from command line while building. So I added to qmake:
LIBS += -L/home/jakub/rpi-qt/sysroot/usr/lib/arm-linux-gnueabihf
Now it works fine. So try using line in *.pro file but change your <path to sysroot>.
LIBS += -L<Path_to_sysroot>/sysroot/usr/lib/arm-linux-gnueabihf