+Prerequisites
+-------------
+The test system itself requires:
+
+ - bash(1) version 4.0 or newer
+
+Without bash 4.0+ the tests just refuse to run.
+
+Some tests require external dependencies to run. Without them, they
+will be skipped, or (rarely) marked failed. Please install these, so
+that you know if you break anything.
+
+ - GNU tar(1)
+ - dtach(1)
+ - emacs(1)
+ - emacsclient(1)
+ - gdb(1)
+ - gpg(1)
+ - python(1)
+
+If your system lacks these tools or have older, non-upgreable versions
+of these, please (possibly compile and) install these to some other
+path, for example /usr/local/bin or /opt/gnu/bin. Then prepend the
+chosen directory to your PATH before running the tests.
+
+e.g. env PATH=/opt/gnu/bin:$PATH make test
+
+For FreeBSD you need to install latest gdb from ports or packages and
+provide path to it in TEST_GDB environment variable before executing
+the tests, native FreeBSD gdb does not not work. If you install
+coreutils, which provides GNU versions of basic utils like 'date' and
+'base64' on FreeBSD, the test suite will use these instead of the
+native ones. This provides robustness against portability issues with
+these system tools. Most often the tests are written, reviewed and
+tested on Linux system so such portability issues arise from time to
+time.
+
+