dnl to do i686-linux builds on x86_64-linux machines.
AC_CHECK_HEADERS([sys/personality.h])
- dnl Check for <linux/fs.h> (for immutable file support).
- AC_CHECK_HEADERS([linux/fs.h])
-
dnl Determine the appropriate default list of substitute URLs (GnuTLS
dnl is required so we can default to 'https'.)
guix_substitute_urls="https://ci.guix.gnu.org"