Qt Plugins: :-1: error: cannot find -lpnp_basictools : UPDATE with .pro files

[tryRevilo]

Re: Qt Plugins: :-1: error: cannot find -lpnp_basictools

I have been trying for days now to use third party libraries in my simple Qt projects, but to no success so far.

I have tried the Plug & Paint Example and the Plug & Paint Basic Tools Example. The tools/plugandpaint/plugins/basictools/basictools.pro compiles OK, but the tools/plugandpaint/app/app.pro fails to compile:

:-1: error: cannot find -lpnp_basictools
collect2.exe:-1: error: error: ld returned 1 exit status

I have practically copy-pasted the sources from the website to my computer. What could I be missing.

Windows 10

Qt Creator 3.6.0

Based on Qt 5.5.1 (MSVC 2013, 32 bit)
Built on Dec 15 2015 01:01:38
From revision b52c2f91f5

LIBS += your_lib_path/your_lib linux：LIBS += -L your_lib_path -lyour_lib win32：LIBS += your_lib_path/your_lib LIBS += -L lib/pcsc/ -lpcsclite LIBS += lib/pcsc/libpcsclite.a 2.add headers INCLUDEPATH += your_include_path INCLUDEPATH += . /usr/local/include）

app.pro

TARGET = plugandpaint
DESTDIR = ..

QT += widgets

HEADERS        = interfaces.h \
                 mainwindow.h \
                 paintarea.h \
                 plugindialog.h
SOURCES        = main.cpp \
                 mainwindow.cpp \
                 paintarea.cpp \
                 plugindialog.cpp

LIBS           = -L../plugins -lpnp_basictools

if(!debug_and_release|build_pass):CONFIG(debug, debug|release) {
   mac:LIBS = $$member(LIBS, 0) $$member(LIBS, 1)_debug
   win32:LIBS = $$member(LIBS, 0) $$member(LIBS, 1)d
}

# install
target.path = $$[QT_INSTALL_EXAMPLES]/widgets/tools/plugandpaint
INSTALLS += target

CONFIG += install_ok  # Do not cargo-cult this!

basictoolsplugin.pro

TEMPLATE      = lib
CONFIG       += plugin static
QT           += widgets
INCLUDEPATH  += ../../app
HEADERS       = basictoolsplugin.h
SOURCES       = basictoolsplugin.cpp
TARGET        = $$qtLibraryTarget(pnp_basictools)
DESTDIR       = ../../plugins

# install
target.path = $$[QT_INSTALL_EXAMPLES]/widgets/tools/plugandpaint/plugins
INSTALLS += target

CONFIG += install_ok  # Do not cargo-cult this!**bolded text**

[mrjj]

Hi

• use third party libraries

Those are normally NOT Qt plugins but so/dll files ?

http://doc.qt.io/qt-5/third-party-libraries.html

Are you trying to make a Qt plugin that uses a external "LIB" ?

[tryRevilo]

@mrjj Hi. Thank you for the response. Why is my implementation not working?

[mrjj]

@tryRevilo

Hi
Im not sure what you are building. If its just a normal Qt plugin and there is no third party libraries also then
most likely, this is not true

LIBS = -L../plugins -lpnp_basictools

it says that from the .pro and one step back there is plugins folder and in that folder
it can find the plugin called pnp_basictools
This must be true. The file must be placed there and in that path.