gvim startup time on Kubuntu 20.04 increased

[John Little]

I upgraded from Kubuntu 19.10 to 20.04.  gvim now has an annoying ~600 ms delay on starting, which --startuptime says occurs at "starting GUI".  On 19.10 the delay is ~140 ms.    This applies to all the recent versions of gvim I've tried up to 8.2.683, with --clean, -u NONE -U NONE, even running the exact same executable: gvim  built on 20.04 running on 19.10 does not have the delay, gvim built on 19.10 running on 20.04 does.  Applying set go= in .vimrc doesn't help.

After installing vim-gtk3 from the respective repositories, some 8.1 version, the delay does not occur booted to a live iso of Ubuntu 20.04, nor Xubuntu 20.04.  It does booted to the Kubuntu live iso.  These findings also apply to running the vim built on Kubuntu 20.04, booted from the isos, except that the delay on Xubuntu is only 80 ms.

So this seems to be a KDE plasma problem.  Does anyone with KDE plasma 5.18.4, or 5.18, on another distro see this? 

What might be the cause of this?

Regards, John Little

[John Little]

I stumbled on what amounts to a solution for me.  The default GTK3 theme in Kubuntu is called "Breeze", as is the default KDE and GTK2 theme.  Changing the theme to a non-Breeze one reduces the "starting GUI" delay to about 200 ms, depending on the theme. This is much less noticeable. 

IMO it's crazy that Vim, despite sourcing over 60 scripts, can start in less than 100 ms, and the GUI can need much longer than that.

Regards, John Little