1--- a/libbuild2/cc/pkgconfig-libpkgconf.cxx
2+++ b/libbuild2/cc/pkgconfig-libpkgconf.cxx
3@@ -84,7 +84,7 @@ namespace build2
4 static bool
5 pkgconf_error_handler (const char* msg,
6 const pkgconf_client_t*,
7- const void*)
8+ void*)
9 {
10 error << runtime_error (msg); // Sanitize the message (trailing dot).
11 return true;