Problem with -isystem in Makefile generated by qmake with Qt5.6.2 and Qt5.7.1 on debian stretch and freeBSD
I have had one problem (when building one Qt app)in the makefile generated by qmake of Qt5.6.2 on FreeBSD 11 and of Qt5.7.1 on debian 9 stretch.
there are some -isystem in the include paths and for example on debian it gives me one error on include_next<stdlib.h> in cstdlib.if I remove the -isystem and I put -I before the paths I can build my project.
from what come this -isystem and for what purpose is it ?
@stephane78 Can you show your pro file?
@jsulm Also: do you execute qmake on both FreeBSD and Debian? (I hope you're not copying the makefiles).
@jsulm no I execute two differents qmake on these both system but I have seen that i have had the same problem.
the beginning of my .pro :```
QT += core gui
QT += network
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = MyApp
TEMPLATE = app
CONFIG += release c++11 linux thread
CONFIG -= console
INCLUDEPATH += "/usr/include"
LIBS += -L'/usr/lib/x86_64-linux-gnu/' -lcrypto -lssl -lpthread
@jsulm, the instruction -isystem is generated by the qmake of recent versions of Qt in the makefile. (probably on unix systems)