* Zack Weinberg: > 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)? The latest installment of this issue is here: configure.ac: Define _DEFAULT_SOURCE along with _XOPEN_SOURCE <https://github.com/samtools/htslib/pull/1711> I wasn't aware of this change from 33c26d2700f927432c756ccf7a4fc89403d35b95 ("Fix port of AC_FUNC_MMAP"), or maybe I just forgot about it: +#ifndef getpagesize +# ifdef _SC_PAGESIZE +# define getpagesize() sysconf (_SC_PAGESIZE) +# elif defined _SC_PAGE_SIZE +# define getpagesize() sysconf (_SC_PAGE_SIZE) +# elif HAVE_GETPAGESIZE +int getpagesize (); +# else This should indeed isolate this test from the outcome of the getpagesize check because it now prefers sysconf. I can't test this with htslib unfortunately because I'm not able to build autoconf from sources for some reason. Thanks, Florian