Hi Van - first, I've copied your messages to the bug tracker, so please use bug-automake@gnu.org and the given subject line so things stay in the bug going forward. https://debbugs.gnu.org/cgi/bugreport.cgi?bug=59099 (Except my resend of your reply didn't get attached. I don't know why not. Will try to figure that out. For the record, your msg is here: https://lists.gnu.org/archive/html/automake/2022-11/msg00001.html )
I am not sure which interface to choose for the new feature. I see few possible approaches: Your summary is admirable :). I think we should have Jim and/or other more experienced Automakers weigh in before you start coding. But here are my comments. Disadvantage is that both directories are not writable by non-privileged user. Since the purpose of the new feature is to support per-project helper files (right?), a single system directory doesn't seem right. Let's not mess around with system directories if we can help it. 2. Let automake maintain the *list* of directories to be searched for aux files. Sounds right. In such case, the --libdir option (and the AUTOMAKE_LIBDIRS environment variable) will insert the given directory to the beginning (or to the end?) of the list. Multiple --libdir options are allowed. I like the idea in general. Is there any existing code relying on the fact that automake ignores standard directory if the --libdir option is specified? The answer to the question "does anything depend on X", for any Automake (or Autoconf) behavior X, is yes. So I think we must not change existing behavior of --libdir or AUTOMAKE_LIBDIR. Instead, we can add to it. What comes to mind follows your typo above :) ... have a new option/envvar --libdirs/AUTOMAKE_LIBDIRS which maintains an independent list of directories to search. I think the new dirs should be searched after the libdir/AUTOMAKE_LIBDIR directory. I think the list of dirs should be searched in the order specified: --libdirs foo --libdirs bar would search foo then bar. As with --libdir/AUTOMAKE_LIBDIR, if --libdirs is specified, it would override (completely) AUTOMAKE_LIBDIRS. No such "extra" directories would be searched by default. Does that reasonably solve your original request? Also, it is not clear to me, should it affect searching for *.am files or not. For consistency, I think the new searching should look for the same files as the existing searching. Presumably that will be easiest/cleanest to implement, too. In general, the closer the new behavior is to the existing, the easier I think it will be to understand (and implement and document). Wdyt? --thanks, karl.