swan: Use custom PDFExporter command to reduce PDF export time

Force the PDF exporter command to use the temporary user home, to
prevent it touching the user EOS and with that reduce the time it takes
for a notebook to be exported to PDF

Author: PMax5

swan/python/jupyter_server_config.py

@@ -30,3 +30,9 @@
     c.ServerApp.default_url = '/lab'
 else:
     c.ServerApp.default_url = '/projects'
+
+user = os.environ.get('USER')
+# Change the HOME environment variable to the local user home instead of EOS
+# to prevent xelatex from touching EOS during the PDF conversion and so
+# reduce the time it takes to convert a PDF (including preventing timeouts).
+c.PDFExporter.latex_command = ['env', f'HOME=/home/{user}' , 'xelatex', '-quiet', '{filename}']