diff -Paur --no-dereference -- libcairo.upstream/build/config.sub libcairo/build/config.sub
--- libcairo.upstream/build/config.sub
+++ libcairo/build/config.sub
@@ -1348,7 +1348,7 @@
 	      | -hpux* | -unos* | -osf* | -luna* | -dgux* | -auroraux* | -solaris* \
 	      | -sym* | -kopensolaris* \
 	      | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \
-	      | -aos* | -aros* \
+	      | -aos* | -aros* | -sortix* \
 	      | -nindy* | -vxsim* | -vxworks* | -ebmon* | -hms* | -mvs* \
 	      | -clix* | -riscos* | -uniplus* | -iris* | -rtu* | -xenix* \
 	      | -hiux* | -386bsd* | -knetbsd* | -mirbsd* | -netbsd* \
diff -Paur --no-dereference -- libcairo.upstream/build/configure.ac.warnings libcairo/build/configure.ac.warnings
--- libcairo.upstream/build/configure.ac.warnings
+++ libcairo/build/configure.ac.warnings
@@ -36,16 +36,6 @@
 dnl We also abuse the warning-flag facility to enable other compiler
 dnl options.  Namely, the following:
 
-dnl -flto working really needs a test link, not just a compile
-
-safe_MAYBE_WARN="$MAYBE_WARN"
-MAYBE_WARN="$MAYBE_WARN -flto"
-AC_TRY_LINK([],[
-	int main(int argc, char **argv) { return 0; }
-],[],[
-	MAYBE_WARN="$safe_MAYBE_WARN"
-])
-
 MAYBE_WARN="$MAYBE_WARN -fno-strict-aliasing -fno-common"
 
 dnl Also to turn various gcc/glibc-specific preprocessor checks
diff -Paur --no-dereference -- libcairo.upstream/configure libcairo/configure
--- libcairo.upstream/configure
+++ libcairo/configure
@@ -18159,33 +18159,6 @@
 MAYBE_WARN="$MAYBE_WARN -erroff=E_ENUM_TYPE_MISMATCH_ARG \
 			-erroff=E_ENUM_TYPE_MISMATCH_OP"
 
-
-
-safe_MAYBE_WARN="$MAYBE_WARN"
-MAYBE_WARN="$MAYBE_WARN -flto"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-	int main(int argc, char **argv) { return 0; }
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-
-else
-
-	MAYBE_WARN="$safe_MAYBE_WARN"
-
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-
 MAYBE_WARN="$MAYBE_WARN -fno-strict-aliasing -fno-common"
 
 MAYBE_WARN="$MAYBE_WARN -Wp,-D_FORTIFY_SOURCE=2"
@@ -31800,7 +31773,7 @@
 
 
 
-if pkg-config --exists 'pixman-1 >= 0.27.1'; then
+if ${PKG_CONFIG:-pkg-config} --exists 'pixman-1 >= 0.27.1'; then
 
 $as_echo "#define HAS_PIXMAN_GLYPHS 1" >>confdefs.h
 
diff -Paur --no-dereference -- libcairo.upstream/configure.ac libcairo/configure.ac
--- libcairo.upstream/configure.ac
+++ libcairo/configure.ac
@@ -662,7 +662,7 @@
   image_LIBS=$pixman_LIBS
 ])
 
-if pkg-config --exists 'pixman-1 >= 0.27.1'; then
+if ${PKG_CONFIG:-pkg-config} --exists 'pixman-1 >= 0.27.1'; then
     AC_DEFINE([HAS_PIXMAN_GLYPHS], 1, [Enable pixman glyph cache])
 fi