Originally Posted by kovidgoyal
Create a simple one line script to lauch sigil that sets the env var and use that script in open with
That is similar to what I had done. I created a local copy of sigil desktop and changed
Exec=sigil to Exec=bash -c "LC_ALL=en_GB.utf8 sigil" which works OK to start Sigil but of course not with open with in Calibre.
I tried your script and and can use it to start Sigil inside and outside Calibre the only problem is that starting it via open with opens an empty Sigil file not the one I need to edit.