Re: Lilypond taking forever to typeset

[David Kastrup]

Hi Mojca,

that sounds bad.  I'm forwarding this to the bug list and hope we'll get
some feedback there.  There have been numerous changes in font handling
in the last few versions as well as several default font changes.

So if you have some manner of reproducing the problem it would be nice
if you could check against something like version 2.19.40 so that we can
at least figure out whether it is the most recent batch of changes which
is responsible here.


Mojca Miklavec <address@hidden> writes:

> Hi,
>
> JFYI:
>
> The file you sent me didn't compile with the stable version (even if I
> just change the version string), so I initially wanted to install the
> devel version of LilyPond via MacPorts, but since I'm on an
> "unsupported" OS (dated back from 2011, OS X Lion), it would take
> forever to compile all of its dependencies.
>
> So I fetched the devel version from your site, but nothing happened
> when I tried to compile the file ... for just about forever.

Note to Hosoda-san: this file did not do much in terms of code but
employed chord mode and possibly lyrics.  Something like

<< c \lyrics { x } \chords { c } >>

would likely have similar impact.

> I then started investigating which files the lilypond binary was
> accessing while eating 100% of the processor speed.
>
> It turned out that lilypond is iterating through all of the system
> fonts, taking a couple of seconds per font and insanely long for
> LastResort.ttf (you may probably google for that font which had
> similar problems with luatex). I remember seeing exactly the same
> symptoms earlier, but at that point I didn't try to investigate, I
> just deleted lilypond and installed it from scratch. Weird enough the
> stable version didn't experience that problem unless I had some old
> cache still stored somewhere on the disk.
>
> It eventually finished processing the first file after 10 minutes.
>
> It might be worth looking into this and at least warning the user that
> font cache is being generated and that this might take a while,
> otherwise many newbies will just kill lilypond before the ten minutes
> are over.

Anybody with a guess regarding the origin of the problem, whether it is
a one-time cost we are talking about, when it might get retriggered, and
what we may do about it?

-- 
David Kastrup