I'm guessing the original issue has something to do with a python plugin subprocessing a c++ program that was subprocessing a python plugin that was subprocessing a java program.
Actually, I see in the Open With plugin code that there's a special handler for Sigil on Windows that involves the PATH being deleted from the retrieved os.environ dictionary before launching the Sigil subprocess. I'm sure something necessitated that bit of trickeration, but unfortunately, it also means that any Sigil plugin that relies on the ability to launch an external program without the full path to the exe is doomed to failure whenever Sigil is launched via the Open With calibre plugin on Windows. The "Open With" plugin also first blanks the LD_LIBRARY_PATH (for all launched subprocesses) on Linux, so any Sigil plugins that rely on using/diddling the LD_LIBRARY_PATH will be doomed to similar failures when Sigil is launched via the OW plugin on Linux.
Good to know that the new native "Open With" calibre feature eliminates the problem.
