On Wed, Dec 13, 2023, at 4:27 AM, Florian Weimer wrote: > I'm not aware of any generic issues in current-ish autoconf. Some > macros needed fixing, but not the basic ones modified by those two > commits. Even autoconf 2.69 is mostly fine—you have to go back much > farther to find versions with generic issues. Good to hear. I'd be testing these things myself but I've gotten so confused about which changes are actually in which released versions of which compilers that I wouldn't have any confidence in anything I did. > Some concern has been expressed that the AC_FUNC_MMAP test fails > incorrectly if getpagesize is detected, but does not have a > prototype in <unistd.h>. One way this can happen is if a project > does not use AC_USE_SYSTEM_EXTENSIONS, but says (with glibc) > _XOPEN_SOURCE directly, but not _DEFAULT_SOURCE. Reportedly, it > also happens on Darwin. I think the autoconf position is that these > projects should use AC_USE_SYSTEM_EXTENSIONS instead, so no attempt > has been made to fix it. Paul Eggert made some changes back in May that attempt to address this: commits 028526149ee804617a302ccef22cc6adbda681b0 and 33c26d2700f927432c756ccf7a4fc89403d35b95. Do you have a minimized test case for the problem (both the original problem and any remaining issues you're aware of are useful to me)? zw