The Tcl package contains the Tool Command Language. Estimated build time: &tcl-time-tools; Estimated required disk space: &tcl-compsize-tools; &aa-tcl-down; &aa-tcl-dep;   This package and the next two are only installed to be able to run the test suites for GCC and Binutils. Installing three packages just for testing purposes may seem like overkill, but it is very reassuring, if not essential, to know that our most important tools are working properly. Even if you are not running the test suites here in this chapter as per our recommendation, these packages are still required for the test suites in the next chapter. Prepare Tcl for compilation: cd unix ./configure --prefix=/tools Build the package: make As discussed earlier, we don't recommend running the test suites for the temporary tools here in this chapter. If you still want to run the Tcl test suite anyway, the following command will do so. However, you should be aware that the Tcl test suite is sometimes known to experience failures under certain host conditions that are not fully understood. Therefore, test suite failures here are not surprising, but are not considered critical: TZ=UTC make test The meaning of the make parameter: TZ=UTC: This sets the time zone to Coordinated Universal Time (UTC) also known as Greenwich Mean Time (GMT), but only for the duration of the test suite run. This ensures the clock tests are exercised correctly. More information on the TZ environment variable will be given later on in . Sometimes, package test suites will give false failures. You can consult the LFS Wiki at to verify that these failures are normal. This applies to all tests throughout the book. Install the package: make install Do not remove the tcl&tcl-version; source directory yet, as the next package will need its internal headers. Make a necessary symbolic link: ln -s tclsh8.4 /tools/bin/tclsh &aa-tcl-shortdesc; &aa-tcl-desc;