Makefile: not running configure first is so yesterday:

Make should only run configure if config.var already exists:

    $ make
    ./configure --reconfigure
    ./configure: 65: .: config.vars: not found
    ./configure --reconfigure
    ./configure: 65: .: config.vars: not found
    Makefile:179: recipe for target 'ccan/config.h' failed
    make: *** [ccan/config.h] Error 2

Makefile

@@ -176,6 +176,7 @@ LDLIBS = -L/usr/local/lib -lm -lgmp -lsqlite3 -lz $(COVFLAGS)
 default: all-programs all-test-programs
 
 config.vars ccan/config.h: configure
+	@if [ ! -f config.vars ]; then echo 'The 1990s are calling: use ./configure!' >&2; exit 1; fi
 	./configure --reconfigure
 
 include external/Makefile