libUSB on MaxOs Sierra LINKER Problem (can't map file, errno=22)

Barcley

Hey folks,

I'am getting crazy while trying to get the libusb library to run. Iam using MacOs Sierra with Qt Creator 4.2.1.
I installed libusb via git.

I always get the error message: can't map file, errno=22

I think its just a linker problem. In the following code snippet and image my file path and the PRO-file are shown.

Greetings Tobi

#-------------------------------------------------
#
# Project created by QtCreator 2017-02-08T23:15:27
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = USBTMC
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

LIBS += /Users/tobias/Qt/includes/libusb/libusb£ 

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

INCLUDEPATH += /Users/tobias/Qt/includes/libusb/libusb

SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

Link to image: https://drive.google.com/open?id=0B4sCAnYsepnkak1nWklnaVV5VEk

jsulm

@Barcley Shouldn't it be

LIBS += -L/Users/tobias/Qt/includes/libusb -lusb

?
Also why is the library located in "includes" directory?

Barcley

I just named the folder, in wich I cloned the git repository, "includes".

Why do you add a "-L" in front of the path and what is "-lusb"?
I have no library named "lusb"

Thanks for your help :)

jsulm

@Barcley Please read http://doc.qt.io/qt-5/third-party-libraries.html
-L is used to specify the directory where to search for the lib
-l specifies the library name (without lib prefix and without any suffixes)
That means:

LIBS += -L/Users/tobias/Qt/includes/libusb -lusb

look in directory /Users/tobias/Qt/includes/libusb for a library named libusb*

Barcley

@jsulm Ah thank you. Good to know :)

I solved the problem with installing the library with homebrew:

brew install libusb

And set the paths in the .PRO-file to:

# Link LIBUSB library
LIBS += -L/usr/local/Cellar/libusb/1.0.21/lib -lusb-1.0
# Path to LIBUSB library
INCLUDEPATH += /usr/local/Cellar/libusb/1.0.21/include/libusb-1.0