+@item
+If you are happy with the results, then stop now.
+
+If you want to continue programming, then make any additional code
+changes, and continue.
+
+@item
+Compile the source with @samp{make} as usual.
+
+@item
+To re-check files that differed between the initial
+@samp{make@tie{}test-baseline} and your post-changes
+@samp{make@tie{}check}, run:
+
+@example
+make test-redo
+@end example
+
+This updates the regression list at @file{out/test-results/index.html}.
+It does @emph{not} redo @file{test-output-distance.ly}.
+
+@item
+When all regressions have been resolved, the output list will be empty.
+
+@item
+Once all regressions have been resolved, a final check should be completed
+by running:
+
+@example
+make test-clean
+make check
+@end example
+
+This cleans the results of the previous @samp{make@tie{}check}, then does the
+automatic regression comparison again.
+
+@end enumerate
+
+@advanced{
+Once a test baseline has been established, there is no need to run it again
+unless git master changed. In other words, if you work with several branches
+and want to do regtests comparison for all of them, you can
+@code{make test-baseline} with git master, checkout some branch,
+@code{make} and @code{make check} it, then switch to another branch,
+@code{make test-clean}, @code{make} and @code{make check} it without doing
+@code{make test-baseline} again.}
+
+
+@node Finding the cause of a regression
+@section Finding the cause of a regression
+
+Git has special functionality to help tracking down the exact
+commit which causes a problem. See the git manual page for
+@code{git bisect}. This is a job that non-programmers can do,
+although it requires familiarity with git, ability to compile
+LilyPond, and generally a fair amount of technical knowledge. A
+brief summary is given below, but you may need to consult other
+documentation for in-depth explanations.
+
+Even if you are not familiar with git or are not able to compile
+LilyPond you can still help to narrow down the cause of a
+regression simply by downloading the binary releases of different
+LilyPond versions and testing them for the regression. Knowing
+which version of LilyPond first exhibited the regression is
+helpful to a developer as it shortens the @code{git bisect}
+procedure.
+
+Once a problematic commit is identified, the programmers' job is
+much easier. In fact, for most regression bugs, the majority of
+the time is spent simply finding the problematic commit.
+
+More information is in @ref{Regression tests}.
+
+@subheading git bisect setup
+
+We need to set up the bisect for each problem we want to
+investigate.
+
+Suppose we have an input file which compiled in version 2.13.32,
+but fails in version 2.13.38 and above.
+
+@enumerate
+@item
+Begin the process:
+
+@example
+git bisect start
+@end example
+
+@item
+Give it the earliest known bad tag:
+
+@example
+git bisect bad release/2.13.38-1
+@end example
+
+(you can see tags with: @code{git tag} )
+
+@item
+Give it the latest known good tag:
+
+@example
+git bisect good release/2.13.32-1
+@end example
+
+You should now see something like:
+@example
+Bisecting: 195 revisions left to test after this (roughly 8 steps)
+[b17e2f3d7a5853a30f7d5a3cdc6b5079e77a3d2a] Web: Announcement
+update for the new @qq{LilyPond Report}.
+@end example
+
+@end enumerate
+
+@subheading git bisect actual
+
+@enumerate
+
+@item
+Compile the source:
+
+@example
+make
+@end example
+
+@item
+Test your input file:
+
+@example
+out/bin/lilypond test.ly
+@end example
+
+@item
+Test results?
+
+@itemize
+@item
+Does it crash, or is the output bad? If so:
+
+@example
+git bisect bad
+@end example
+
+@item
+Does your input file produce good output? If so:
+
+@example
+git bisect good
+@end example
+
+@end itemize
+
+@item
+Once the exact problem commit has been identified, git will inform
+you with a message like:
+
+@example
+6d28aebbaaab1be9961a00bf15a1ef93acb91e30 is the first bad commit
+%%% ... blah blah blah ...
+@end example
+
+If there is still a range of commits, then git will automatically
+select a new version for you to test. Go to step #1.
+
+@end enumerate
+
+@subheading Recommendation: use two terminal windows
+
+@itemize
+@item
+One window is open to the @code{build/} directory, and alternates
+between these commands:
+
+@example
+make
+out/bin/lilypond test.ly
+@end example
+
+@item
+One window is open to the top source directory, and alternates
+between these commands:
+
+@example
+git bisect good
+git bisect bad
+@end example
+
+@end itemize
+
+
+@node Memory and coverage tests
+@section Memory and coverage tests
+
+In addition to the graphical output of the regression tests, it is
+possible to test memory usage and to determine how much of the source
+code has been exercised by the tests.
+
+@subheading Memory usage
+
+For tracking memory usage as part of this test, you will need
+GUILE CVS; especially the following patch:
+@smallexample
+@uref{http://www.lilypond.org/vc/old/gub.darcs/patches/guile-1.9-gcstats.patch}.
+@end smallexample
+
+@subheading Code coverage
+
+For checking the coverage of the test suite, do the following
+
+@example
+./scripts/auxiliar/build-coverage.sh
+@emph{# uncovered files, least covered first}
+./scripts/auxiliar/coverage.py --summary out-cov/*.cc
+@emph{# consecutive uncovered lines, longest first}
+./scripts/auxiliar/coverage.py --uncovered out-cov/*.cc
+@end example