what is reason behind below error when we execute make command ?

[Qt embedded developer]

g++ -Wl,-O1 -o LaserModule -lQt5Gui -lQt5Core -lGLESv2 -lpthread
/usr/lib/gcc/arm-linux-gnueabihf/6/../../../arm-linux-gnueabihf/Scrt1.o: In function _start': (.text+0x44): undefined reference to main'
collect2: error: ld returned 1 exit status
Makefile:125: recipe for target 'LaserModule' failed
make: *** [LaserModule] Error 1

[jsulm]

@Qt-embedded-developer said in what is reason behind below error when we execute make command ?:

undefined reference to main'

Well, main() function is missing. Make sure you have a cpp file with main() function...

[JonB]

@Qt-embedded-developer said in what is reason behind below error when we execute make command ?:

g++ -Wl,-O1 -o LaserModule -lQt5Gui -lQt5Core -lGLESv2 -lpthread

Further to @jsulm correctly stating that main function is missing. If you look at this link line it outputs to LaserModule but it does not seem to have any input module of your own at all. For example, if you have a main.cpp we should be seeing main.o, or if you have a LaserModule.cpp we should be seeing LaserModule.o, among the files being linked. So look at your project/how this line was generated.