···254 "--enable-lto"
255 ];
25600000000257 makeFlags = [
258 # gcc runs multi-threaded LTO using make and does not yet detect the new fifo:/path style
259 # of make jobserver. until gcc adds support for this we have to instruct make to use this
···254 "--enable-lto"
255 ];
256257+ env.CXXFLAGS = toString (
258+ lib.optionals (lib.versionAtLeast lowdown.version "1.4.0") [
259+ # Autotools based build system wasn't updated with the backport of
260+ # https://github.com/NixOS/nix/pull/12115, so set the define explicitly.
261+ "-DHAVE_LOWDOWN_1_4"
262+ ]
263+ );
264+265 makeFlags = [
266 # gcc runs multi-threaded LTO using make and does not yet detect the new fifo:/path style
267 # of make jobserver. until gcc adds support for this we have to instruct make to use this