https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78581
--- Comment #1 from Phil Ruffwind <rf at rufflewind dot com> ---
After some more testing, it looks the following environment variable must be
set to trigger the crash:
C_INCLUDE_PATH=XXXXXXXXXXXXXXXXXXXXXXXX:
The variable must contain at least 25 characters, and the last character must
be a colon.
