The issue hasn't repeated in the past few days .. I'd hate if this has to do with me restarting my machine. (As a side: My machine had an uptime of about a year, and I restarting it fixed the problem that gdb wasn't able to access ptrace. The whole reason I wanted that to work was to use gdb to debug this problem when it occurred next.)
After the machine restart, the gdb issue resolved, and this line disappearing issue also "seems" to have.. disappeared.
Nope, it is back!
Thanks to Romanos, I tried to see if this issue had anything to do with tooltips and it almost always happens when hovering mouse over stuff in modeline, waiting for tooltips to appear.
I have yet to find a recipe from emacs -Q, but below is a GIF recording:
- Hovering mouse for tool-tips makes the line nums disappear (only for some tooltips though)
- Clicking anywhere in the buffer brings the line nums back
I do that a couple of times in that GIF.
@Eli: About setting display-line-numbers globally, that did not help..
I evaluated:
(setq-default display-line-numbers t)
(So now even fundamental-mode buffers have line numbers.)
But even after, the hover-over-modeline magic trick faithfully reproduces this issue at least on my config.
Now, I will try to cook an emacs -Q recipe.
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Latest emacs version info (Note that I am on RHEL 6.6, GTK2):
Emacs version: GNU Emacs 26.0.90 (build 4, x86_64-pc-linux-gnu, GTK+ Version 2.24.23)
of 2017-10-16, built using commit 16e85456e70174f1d97fc5a7cd8a199b8f0e7e70.
./configure options:
--with-modules --prefix=/home/kmodi/usr_local/apps/6/emacs/emacs-26 '--program-transform-name=s/^ctags$/ctags_emacs/' 'CPPFLAGS=-I/home/kmodi/usr_local/6/include -I/usr/include/freetype2 -I/usr/include' 'CFLAGS=-ggdb3 -O0' 'CXXFLAGS=-ggdb3 -O0' 'LDFLAGS=-L/home/kmodi/usr_local/6/lib -L/home/kmodi/usr_local/6/lib64 -ggdb3'
Features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK2 X11 MODULES