https://bugs.gentoo.org/924211
https://gitlab.gnome.org/GNOME/perl-cairo/-/issues/2

--- a/CairoSurface.xs
+++ b/CairoSurface.xs
@@ -389,7 +389,7 @@ cairo_status_t
 cairo_surface_set_mime_data (cairo_surface_t *surface, const char *mime_type, SV *data);
     PREINIT:
 	const unsigned char *mime_data;
-	unsigned long length;
+	STRLEN length;
     CODE:
 	SvREFCNT_inc (data);
 	mime_data = (const unsigned char *) SvPV(data, length);