Re: 2.19.47 long compile times

[Trevor Bača]

On Wed, Sep 14, 2016 at 10:02 AM, Masamichi Hosoda <address@hidden>
wrote:

> >> Hi,
> >>
> >> The new 2.19.47 is taking about 40 seconds to compile a one-note test
> >> file.
> >> (MacOS X x86.)
> >>
> >> In my past experience, new LilyPond builds sometimes take 30 or 40
> >> seconds
> >> to compile *on the very first run after install* (presumably to update
> >> the
> >> font cache, or something similar). But 2.19.47 is taking 40 seconds
> >> *on
> >> every run*.
> >>
> >> Trevor.
> >
> >
> > There was something _similar_ reported on Windows 10, although the
> > slow-down occurred between 19.42 and 19.43.  In this case, it appeared
> > that the problem was fixed by deleting all the files in
> > c:\users\yourusername\.lilypond-fonts.cache-2.  Perhaps a similar
> > approach will work for the Mac?
> >
> > --
> > Phil Holmes
>
> If you would like to delete the fontconfig cache files in OSX,
> cache directory might be `~/.lilypond-fonts.cache-2`.
> http://lists.gnu.org/archive/html/bug-lilypond/2016-07/msg00050.html
>
> So If I understand correctly, the following command can delete them.
>
> $ rm -fr ~/.lilypond-fonts.cache-2
>

Summary: removing the files in ~/.lilypond-fonts.cache-2 does *not* fix the
problem of ultra-slow compilation times under OSX for LilyPond versions
2.19.47 and 2.19.48.

Details:

1. The directory ~/.lilypond-fonts.cache-2 does indeed exist for OSX
LilyPond installs (analogously to Windows installs).

2. The three files resident in ~/lilypond-fonts.cache-2 for LilyPond
versions 2.19.46, 47 and 48 under OSX are:

 $ ls ~/.lilypond-fonts.cache-2/
84c0f976e30e948e99073af70f4ae876-i686-apple-darwin8.cache-7
b0a71e6bf6a8a1a908413a823d76e21f-i686-apple-darwin8.cache-7
ce2f012eabd1de3f1e401def0f51e425-i686-apple-darwin8.cache-7

3. Removing the files in ~/.lilypond-fonts.cache-2 is harmless. You can do
so using ...

   rm ~/.lilypond-fonts.cache-2/*

... as the command.

4. If you remove the files in ~/.lilypond-fonts.cache-2 then LilyPond will
repopulate the directory the next time you run LilyPond. This process
("rebuilding the font cache") takes awhile. Usually something like 40
seconds.

5. Healthy versions of LilyPond rebuild the font cache on first run (after
install) only.

6. LilyPond versions 2.19.42, 43, 44, 45 and 46 under OSX are "healthy"
according to this definition. (This differs from the situation reported by
Windows users. Windows users reported a problem starting with LilyPond
version 2.19.43.)

7. LilyPond versions 2.19.47 and 48 are "unhealthy": these two most recent
versions of LilyPond appear to rebuild the font cache on *EVERY* run of
LilyPond, meaning that every run of LilyPond takes 40 seconds or more.

It is, of course, better that these problems appear in development releases
of LilyPond (as opposed to stable releases of LilyPond) since we warn users
about potential risks with development versions of the program.

But there is still a real risk with this slow-compilation problem appearing
in development releases: many experienced users follow along with the
development releases and recompile our existing, complex scores with each
new release, effectively black box testing each new development release. As
of now I'm no longer able to do this because the slowdown is so severe that
it's now impossible for me to compose (and, therefore, test) with the two
most recent development versions.

Trevor.


-- 
Trevor Bača
www.trevorbaca.com
soundcloud.com/trevorbaca