Provide Makefile variables LIBEVENT_{CFLAGS,CPPFLAGS,LDFLAGS} This will allow a parent package to specify compiler, CPP, and linker flags to a libevent built as a sub-package. Picked-from: #506 Closes: #506 (cherry picked from commit 1a448088e3aef5b6baf161eb0f6d17e18a77313c)