Hello, In glibc 2.23, malloc/Makefile contains: ./malloc/Makefile:$(objpfx)tst-malloc-backtrace: $(common-objpfx)nptl/libpthread.so \ So this is actually hardcoding the directory containing libpthread.so, thus preventing build on systems which use another libpthread than nptl. Shouldn't we introduce a variable to specify that directory? Samuel