https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100932
--- Comment #2 from Nicolas Boulenguez <nicolas at debian dot org> --- I fail to understand how your answer helps anyone. Currently, 'autoconf' fails and 'autoconf -I../config' succeeds. With the change, both would succeed and be equivalent. What is the benefit of requiring a command-line option when the only possible value can be provided as a default? I am using # autoreconf $(computed list of subdirectories) This would be way more difficult if I had to add a different -I option for each subdirectory.