git difftool with visual editor takes 4.5 seconds to open next file

[HassanAhmadAli]

i configured a gui application to be used with git core.editor "vscode" , the application work perfectly as a git mergetool but it takes 4.5 second or more to switch to the next file when running 'git difftool', the issue is not only with vscode as i tried other visual code editors and all of them take long time, but the command runs extremely fast with cli based applications.

then...

i tried using git with wsl in windows and set vscode as the default code editor for git and it takes fraction of a second to switch files git difftool.
both on the same machine git with wsl is very much faster with GUI than git for windows

running git at the last current version , the issue exist with older versions also

[dscho]

While git difftool is a builtin written in C, it spawns git difftool--helper, which is a Unix Shell script.

As a consequence, we must expect a certain degree of slowness: Unix Shell scripts are just not a native thing on Windows and the involved emulation takes time (see here for a fuller explanation of the complexities).

Having said that, you could use the set -x trick to analyze what things are going slowly.