@@ 22,6 22,8 @@ shape :: Font -> Buffer -> [(GlyphInfo, GlyphPos)]
 shape font buf = shapeWithFeatures font buf []
 
 -- FIXME Certain input text can trigger a segfault. I'm not sure how to debug this.
+-- Thought for a moment I fixed it with a semaphore
+-- (seems related to number of threads), but appears not...
 
 data Feature = Feature {
     tag :: String,
 
@@ 60,8 60,8 @@ library
   -- other-extensions:    
   
   -- Other library packages from which modules are imported.
-  build-depends:       base >=4.9 && <5, bytestring, text, text-short, utf8-light
-                       , freetype2 >= 0.2
+  build-depends:       base >=4.9 && <5, freetype2 >= 0.2,
+                       bytestring >= 0.10.8.2 && < 0.12, text >= 1 && <3, utf8-light >= 0.3 && < 1
   pkgconfig-depends:   harfbuzz
   
   -- Directories containing source files.
@@ 75,7 75,7 @@ executable shape-text
   main-is:             Main.hs
 
   -- Other library packages from which modules are imported
-  build-depends:       base >=4.9 && <5, harfbuzz-pure, parallel, bytestring
+  build-depends:       base >=4.9 && <5, harfbuzz-pure, parallel  >= 2.2 && < 4, bytestring
 
   -- Directories containing source files.
   hs-source-dirs:      .