10.9.8 Verify regression tests

In order to avoid breaking LilyPond, it is important to verify that the regression tests succeed, and that no unwanted changes are introduced into the output. This process is described in Regtest comparison.

Typical developer’s edit/compile/test cycle

If you modify any source files that have to be compiled (such as ‘.cc’ or ‘.hh’ files in ‘flower/’ or ‘lily/’), then you must run make before make test-redo, so make can compile the modified files and relink all the object files. If you only modify files which are interpreted, like those in the ‘scm/’ and ‘ly/’ directories, then make is not needed before make test-redo.

Also, if you modify any font definitions in the ‘mf/’ directory then you must run make clean and make before running make test-redo. This will recompile everything, whether modified or not, and takes a lot longer.

Running make check will leave an HTML page ‘out/test-results/index.html’. This page shows all the important differences that your change introduced, whether in the layout, MIDI, performance or error reporting.

You only need to use make test-clean to start from scratch, prior to running make test-baseline. To check new modifications, all that is needed is to repeat make test-redo and make test-check (not forgetting make if needed).

LilyPond — Contributor’s Guide v2.19.81 (development-branch).