INCLUDEPATH += $$PWD DEPENDPATH += $$PWD HEADERS += $$PWD/extract_delegate.h \ $$PWD/compressed_archive.h SOURCES += $$PWD/compressed_archive.cpp if(mingw|unix):!contains(QT_CONFIG, no-pkg-config):packagesExist(libarchive) { message(Using system provided libarchive installation found by pkg-config.) CONFIG += link_pkgconfig PKGCONFIG += libarchive DEFINES += use_libarchive } else:unix:exists(/usr/include/archive.h) { message(Using system provided libarchive installation.) LIBS += -larchive DEFINES += use_libarchive } else { error(Missing dependency: libarchive decompression backend. Please install libarchive on your system) }