The illumos ld doesn't support --export-dynamic.

--- gtk+-3.24.43/testsuite/gtk/meson.build.orig
+++ gtk+-3.24.43/testsuite/gtk/meson.build
@@ -1,7 +1,7 @@
 gtk_tests_export_dynamic_ldflag = []
 
 if cc.get_id() != 'msvc' and cc.get_id() != 'clang'
-  gtk_tests_export_dynamic_ldflag = ['-Wl,--export-dynamic']
+  gtk_tests_export_dynamic_ldflag = []
 endif
 
 tests = [