thom311/libnl — pull request #58 by mgorny (2014-05-25 09:57:40+00:00)
Title: Fix out-of-source build of flex/yacc files

To reproduce the issue:

mkdir _build
cd _build
../configure --disable-dependency-tracking
make

This is going to fail with:

Making all in lib
make[1]: Entering directory '/tmp/libnl/_build/lib'
GEN route/cls/ematch_grammar.c
flex: could not create route/cls/ematch_grammar.c
Makefile:1427: recipe for target 'route/cls/ematch_grammar.c' failed
make[1]: *** [route/cls/ematch_grammar.c] Error 1
make[1]: Leaving directory '/tmp/libnl/_build/lib'

This is because the output directory (`route/cls`) isn't created before the flex/yacc call. In order to fix this, Makefile needs to create it before calling flex/yacc.