Why starting gvim in ConEmu works with a task, but not from command line?

Question

When i enter this in ConEmu:

gvim --windowid %ConEmuBackHWND% -new_console:sH

I get a blank split that after a while says the following:

GUI application (PID=384) was attached to ConEmu:
\Path\To\gvim.exe

While trying to find out what was going wrong i made a "Gvim" task with the following command contents:

gvim --windowid %ConEmuBackHWND% -new_console:sH

(Same as the command i entered above in the command line)
And when i know start the task from the "Create new console" dialog, everything works fine and i get a gvim child window as my right split!

How are the commands being executed from the "Create new console" dialog, and how can i make the above command to spawn a gvim split directly from the console?

Answer 1

ProcessExplorer is very helpful tool to detect problems with environment variables and things... I think you have problem because of variable expansion. Try following

gvim --windowid !ConEmuBackHWND! -new_console:sH

When you run the command with percent signs, the CLI replace variables before ConEmu get the command. So, you were trying to run gvim in new split, but telling it HWND from old split.

When you use exclamation signs, variables are not expanded, ConEmu gets the command untouched, and the !ConEmuBackHWND! is expanding by ConEmu itself in proper moment, after split is created and new variables initialized.