[Bug] PDF Rendering stops after default timeout has been exceeded

[cjlotz]

Describe the bug
When building a large number of PDF's as part of a site, the PDF rendering for the PDF's that have not been completed seems to stop after the default PDF timeout. Setting the environment variable only seems to prevent docfx from immediately terminating after the default timeout expires, but no further rendering seems to take place.

Expected behavior
When increasing the default timeout rendering should continue until all PDF's have been completed or until timeout has expired.

Context (please complete the following information):

• OS: Windows
• Docfx version: [e.g. 2.74.1]