%general-entities; ]> This chapter builds the tools needed to run the tests that the packages have. I.e., make check. Tcl, Expect, and DejaGNU are needed for the GCC and Binutils testsuites, and Tree is used by the Udev testsuite. Installing four packages for testing purposes may seem excessive, but it is very reassuring, if not essential, to know that the most important tools are working properly.