These shaper tests need some specific TrueType fonts. You can get a package of them from http://people.freedesktop.org/~hausmann/harfbuzz-test-fonts-0.1.tar.bz2 In addition you may need two fonts (Mangal and Tunga) from Microsoft Windows for some of the test cases. These fonts are not freely redistributable. The test program looks for them in a fonts/ subdirectory.