Re: old f-clef

[David Kastrup]

Stan Sanderson <address@hidden> writes:

>> On Jun 28, 2017, at 8:53 PM, Stanton Sanderson <address@hidden> wrote:
>> 
>> 
>>> On Jun 28, 2017, at 8:48 PM, Andrew Bernard <address@hidden> wrote:
>>> 
>>> Hi Stan,
>>> 
>>> See LSR:
>>> 
>>> http://lsr.di.unimi.it/LSR/Item?id=900
>>> 
>>> Andrew
>>> 
>> 
>> Andrew,
>> 
>> I should have known to check the LSR but failed to do so.
>
> Now that I’ve had time to try it, the snippet doesn’t compile (with
> 2.19.63) as is, and I’m still wondering
> what I’m doing.
>
> Error message:
>
> Parsing...
> Interpreting music...
> Preprocessing graphical
> objects.../home/gub/NewGub/gub/target/darwin-x86/src/lilypond-git.sv.gnu.org--lilypond.git-release-unstable/lily/grob-property.cc:242:
> failed assertion `scm_is_null (value) || scm_is_eq (value, marker)'
> Exited with exit status 1.

The LSR sample is broken since instead of _returning_ a proper stencil
from the grob callback, it _overrides_ the grob callback with the
stencil.  This confuses LilyPond's internals enough that it will abort.

Basically you need to replace

  (set! (ly:grob-property grob 'stencil)
      [whatever] )

with just
      [whatever]

whenever it occurs in the callback.  Be sure to remove one closing paren
after [whatever] in order to maintain matched parens.

-- 
David Kastrup