Not very often, but do I keep running into issues (fails, segfaults)
related to testing programs compiled with a GCC without offload
configured and then using the system libraries. - That's equivalent
to having the system compiler (or any offload compiler) and
compiling with -foffload=disable.

The problem is that while the program only contains host code,
the run-time library still initializes devices when an API
routine - such as omp_get_num_devices - is invoked. This can
lead to odd bugs as target regions, obviously, will use host
fallback (for any device number) but the API routines will
happily operate on the actual devices, which can lead to odd
errors.

(Likewise issue when compiling for one offload target type
and running on a system which has devices of an other type.)

I assume that that's not a very common problem, but it can be
rather confusing when hitting this issue.

Maybe the proposed wording will help others to avoid this pitfall.
(Or is this superfluous as -foffload= is not much used and, even if,
no one then remembers or finds this none?)

Thoughts?

* * *

It was not clear to me how to refer to libgomp.texi
- Should it be 'libgomp' as in 'info libgomp' or the URL
   https://gcc.gnu.org/onlinedocs/libgomp/ (or filename of the PDF) implies?
- Or as  'GNU Offloading and Multi Processing Runtime Library Manual'
   as named linked to at https://gcc.gnu.org/onlinedocs or on the title page
   of the the PDF - but that name is not repeated in the info file or the HTML
   file.
- Or even 'GNU libgomp' to mirror a substring in the <title> of the HTML file.
I now ended up only implicitly referring that document.

Aside: Shouldn't all the HTML documents start with a <h1> and <title> before
the table of content? Currently, it has:
   <title>Top (GNU libgomp)</title>
and the body starts with
   <h2>Short Table of Contents</h2>

Tobias

PS: In the testsuite, it mostly happens when iterating over
omp_get_num_devices() or when mixing calls to API routines with
device code ('omp target', compute constructs).