* Fix compilation with non glibc.
_SC_NPROCESSORS_ONLN is non standard as defined on https://man7.org/linux/man-pages/man3/sysconf.3.html
It seems to only be on glibc, cf https://www.gnu.org/software/libc/manual/html_node/Processor-Resources.html
* Fix to defined(_SC_NPROCESSORS_ONLN)
#endif
-#if !defined(_WIN32) && !defined(__APPLE__)
+#if !defined(_WIN32) && !defined(__APPLE__) && defined(_SC_NPROCESSORS_ONLN)
static unsigned cpu_count_sysconf = (unsigned)sysconf( _SC_NPROCESSORS_ONLN );
ncpus = minNonZero(ncpus, cpu_count_sysconf);