Re: The Emacs master is much slower than the emacs-27 branch.

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: acm@muc.de,  emacs-devel@gnu.org
> Date: Fri, 04 Dec 2020 17:03:00 +0100
> 
> > Thanks.  This is very strange.  What are the build options and the
> > features in each build? are they identical?
> 
> emacs-27:
> 
> system-configuration-options
> "'CFLAGS=-Og -g3' PKG_CONFIG_PATH=/opt/qt5/lib/pkgconfig"
> 
> system-configuration-features
> "XPM JPEG TIFF GIF PNG RSVG SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL
> GNUTLS LIBXML2 FREETYPE HARFBUZZ XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11
> XDBE XIM MODULES THREADS LIBSYSTEMD PDUMPER LCMS2 GMP"
> 
> master:
> 
> system-configuration-options
> "--with-xwidgets 'CFLAGS=-Og -g3' PKG_CONFIG_PATH=/opt/qt5/lib/pkgconfig"
> 
> system-configuration-features
> "XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY
> INOTIFY ACL GNUTLS LIBXML2 FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS
> GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS LIBSYSTEMD PDUMPER LCMS2"

Could Cairo be the factor here?  Emacs 27 was built without it.