disable plugin test for now, add note to README

README.md

@@ -64,8 +64,9 @@ to document the current shortcomings of this tool.
 * Functions implemented outside Go, such as assembly, aren't garbled since we
   currently only transform the input Go source.
 
-* Since `garble` forces `-trimpath`, plugins built with `-garble` must be loaded
-  from Go programs built with `-trimpath` too.
+* ~~Since `garble` forces `-trimpath`, plugins built with `-garble` must be loaded
+  from Go programs built with `-trimpath` too.~~ Plugins currently do not always
+  work with well with `garble`, period.
 
 ### Runtime API
 

testdata/scripts/plugin.txt

@@ -1,3 +1,5 @@
+skip # TODO: get plugins working properly. See issue #87
+
 [windows] skip 'Go plugins are not supported on Windows'
 
 env GOPRIVATE=test/main