GTK2 version is now available as a constant with the following:
Pike v7.8 release 469 running Hilfe v3.5 (Incremental Pike Frontend)
GTK2.GTK_MINOR_VERSION;
(1) Result: 0
GTK2.MAJOR_VERSION;
(2) Result: 2
GTK2.MINOR_VERSION;
(3) Result: 20
GTK2.MICRO_VERSION;
(4) Result: 1
GTK2.MicroVersion;
(5) Result: 1
GTK2.MajorVersion;
(6) Result: 2
GTK2.MinorVersion;
(7) Result: 20 Terminal closed.
The version string is sprintf("%d.%d.%d",GTK2.MAJOR_VERSION,GTK2.MINOR_VERSION,GTK2.MICRO_VERSION);
Or GTK2.version(), as an array, although this isn't available at pre-compile time (cpp), whereas I believe the above is (should be tested to make sure).