Hallo!
pdp_imageproc_common.c: In function `_sign': pdp_imageproc_common.c:292: warning: use of cast expressions as lvalues is deprecated make[2]: *** [pdp_imageproc_common.o] Error 1
Hm, are you sure, that the gcc-line, that should be above this error shows no traces of -Wall anymore? And there are no other, real errors reported before? Somehow this still looks, like if gcc treats the warning about lvalues as an error, as -Wall would do.
maybe you mean -Werror? because -Werror makes an error out of a warning ... -Wall displays all errors
LG Georg