mklink: Invalid switch from Git Bash

The error

$ cmd //c mklink /J models 'C:\data\models'
Invalid switch - "models".

Why it happens

Git Bash turns arguments that look like Unix paths into Windows paths before it starts a Windows program. That's why cmd's own /c has to be written //c. /J gets the same treatment, so mklink's arguments no longer line up and it rejects the next one as a switch.

The fix

Double the slash, as with //c:

cmd //c mklink //J models 'C:\data\models'

Or turn the rewriting off for one command:

MSYS_NO_PATHCONV=1 cmd /c mklink /J models 'C:\data\models'

Or make the junction from PowerShell, which wants an absolute target:

New-Item -ItemType Junction -Path models -Target C:\data\models

Write the target with backslashes, in quotes. In ../data/models, mklink reads /data as another switch and rejects it.

To remove a junction later, cmd /c rmdir models removes the link alone. Never delete through it recursively: that deletes the files it points to.