diff -ruN old/pkgIndex.tcl new/pkgIndex.tcl
--- old/pkgIndex.tcl	2019-06-26 11:42:01.194722156 -0700
+++ new/pkgIndex.tcl	2019-06-26 11:42:43.690791588 -0700
@@ -11,3 +11,7 @@
 package ifneeded textutil::string   0.8   [list source [file join $dir string.tcl]]
 package ifneeded textutil::expander 1.3.1 [list source [file join $dir expander.tcl]]
 package ifneeded textutil::wcswidth 35.0  [list source [file join $dir wcswidth.tcl]]
+
+if {![package vsatisfies [package provide Tcl] 8.5]} { return }
+
+package ifneeded textutil::patch 0.1 [list source [file join $dir patch.tcl]]