Valid programming errors:

grace-end-2.ly: 				bounds of this piece aren't breakable.
grace-end.ly:					bounds of this piece aren't breakable.
page-breaking-page-count1.ly: 			number of pages is out of bounds
						tried to space systems on a bad number of pages
page-breaking-page-count2.ly:			number of pages is out of bounds (x2)
						tried to space systems on a bad number of pages (x2)
page-breaking-page-count3.ly:			number of pages is out of bounds
						tried to space systems on a bad number of pages
spacing-loose-grace-error.ly:			Cannot determine neighbors for floating column.
						Loose column does not have right side to attach to.
spanner-break-beyond-parent.ly:			Spanner `LyricExtender' is not fully contained in parent spanner. Ignoring orphaned part


Invalid programming errors (FIXME):

incipit.ly:					Grob `InstrumentName' has no interface for property `music' (fix pending)
parenthesize-singlenotes-chords-rests.ly:	Don't know how to parenthesize spanners. (tricky; picks up DynamicLineSpanner when parenthesizing dynamic)

Valid warnings:

beam-quant-standard.ly:				Error in beam quanting. (x5) (might fix, depends on whether this is classed as regression)
beam-quarter.ly:				beam was started here (x2)
clef-warn.ly:					unknown clef type `foo'
finger-chords-order.ly:				Fingering notation for finger number 8/7/6 (deliberately invalid fingers)
glissando-no-break.ly:				forced break was overridden by some other event, should you be using bar checks?
harp-pedals-sanity-checks.ly:			(various error message checks)
harp-pedals.ly:					ditto, though perhaps these should be moved to the above?
markup-music-glyph.ly:				Cannot find glyph UNKNOWN-GLYPH
page-break-warn-forbidden.ly:			forced break was overridden by some other event, should you be using bar checks? (x2)
page-breaking-min-systems-per-page2.ly:		Can't fit systems on page -- ignoring between-system-padding
page-breaking-page-count3.ly:			Can't fit systems on page -- ignoring between-system-padding
page-turn-page-breaking-badturns.ly:		cannot fit the first page turn onto a single page.  Consider setting first-page-number to an even number.
page-turn-page-breaking-repeats.ly:		ditto
repeat-unfold.ly:                               More alternatives than repeats.  Junking excess alternatives
repeat-volta.ly:                                ditto
skiptypesetting-bar-check.ly:                   barcheck failed at: 3/4
stem-tremolo.ly':                               tremolo duration is too long (x2) (perhaps move to new test for invalid durations?)
warn-conflicting-key-signatures.ly:             Two simultaneous key-change events, junking this one

Invalid warnings (FIXME):

beam-multiple-cross-staff.ly:			ignoring too many clashing note columns
dynamics-glyphs.ly:				crescendo too small (due to ragged-right change to #t)
line-dashed-period.ly:				unknown crescendo style: line (old override for crescendoSpanner)
part-combine-tuplet-single.ly:			No tuplet to end (tricky to fix)
property-grace-polyphony.ly:			ignoring too many clashing note columns (broken regression test; grace note messes up voice direction)
quote-during.ly:				ignoring too many clashing note columns ('ignore-collision)
quote.ly:					ditto


MusicXML programming errors:

11c-TimeSignatures-CompoundSimple.ly:		programming error: Grob `TimeSignature' has no interface for property `text' (x5; easily fixed)
11d-TimeSignatures-CompoundMultiple.ly:		ditto
11e-TimeSignatures-CompoundMixed.ly:		ditto
11f-TimeSignatures-SymbolMeaning.ly:		ditto
42a-MultiVoice-TwoVoicesOnStaff-Lyrics.ly:	cyclic dependency: calculation-in-progress encountered for #'X-extent (PaperColumn)
46a-Barlines.ly:				Improbable offset for stencil: inf staff space (x2; bad barline string, type not implemented yet)

MusicXML warnings (valid):

23b-Tuplets-Styles.ly:                          Tuplet brackets of curved shape are not correctly implemented
33e-Spanners-OctaveShifts-InvalidSize.ly:       Invalid octave shift size found: 27. Using no shift.

MusicXML warnings (invalid? CHECKME):

12a-Clefs.ly:                                   unknown clef type `None'
13a-KeySignatures.ly:                           No ordering for key signature alterations (x2) (outlandish keys)
24e-GraceNote-StaffChange.ly:                   cannot find context to switch to
41g-PartNoId.ly:                                no music found in score
45d-Repeats-Nested-Alternatives.ly:             More alternatives than repeats.  Junking excess alternatives
                                                Barcheck failed got 9 expect 10
61g-Lyrics-NameNumber.ly:                       unterminated hyphen; removing
61h-Lyrics-BeamsMelismata.ly:                   unterminated hyphen; removing
99b-Lyrics-BeamsMelismata-IgnoreBeams.ly:       unterminated hyphen; removing