Why library is stripped during install stage

Line 75 in 0e7c272

    
           install -m 0644 $(EXECUTABLE) -D $(DESTDIR)$(libdir)/$(EXECUTABLE).$(VERSION) $(if $(STRIP),--strip --strip-program=$(STRIP))

Usually in yocto libraries will be stripped only during packaging, libraries under image directory are non stripped versions.

May i know the reason why we strip the library during installation? this will limit the debugging of the library right?

If you don't want to strip it, you can set the STRIP environment variable to an empty string in your Bitbake recipe. Yocto will then indeed strip it itself depending on your configuration during the packaging step.