As an MWE, I can test with "emacs -Q" and the following org file:








#+PROPERTY: header-args :eval never-export
# (setq org-export-use-babel t)

#+BEGIN_SRC emacs-lisp :results none
(org-babel-do-load-languages
 'org-babel-load-languages
 '((shell . t)))
#+END_SRC

#+BEGIN_SRC sh :results org raw
for i in $(seq 200); do
echo ""
echo "#+BEGIN_SRC sh :results output :exports results"
echo "echo 'hello, world'"
echo "#+END_SRC"
echo "#+RESULTS:"
echo ": goodbye"
done
#+END_SRC
#+RESULTS:



Execute the first code block to allow execution of the second. Execute the
second code block to generate 200 more. Export. It takes ~6 seconds on my
machine, which seems long but is bearable. Based on the profiling, I think
the reason it takes 1 minute is because the code blocks use <<noweb>>
blocks?. I can verify this with the following MWE:


#+PROPERTY: header-args :eval never-export
# (setq org-export-use-babel t)

#+NAME: foo
#+BEGIN_SRC sh :results verbatim
ls
#+END_SRC
#+RESULTS:

#+NAME: bar
#+BEGIN_SRC sh :results verbatim :noweb yes
<<foo>>
#+END_SRC
#+RESULTS:

#+NAME: baz
#+BEGIN_SRC sh :results verbatim :noweb yes
<<bar>>
#+END_SRC
#+RESULTS:

Repeat the BAZ block with the <<bar>> about 100 times and export this, and
it takes a long time. I killed it after ~30 seconds, because I think I have
my evidence that :noweb yes is the culprit for the slow export.



On Tue, Jun 12, 2018 at 11:15 PM Ken Mankoff <mankoff@gmail.com> wrote:

>
> On Tue, Jun 12, 2018 at 11:07 PM Berry, Charles <ccberry@ucsd.edu> wrote:
>
>>
>> > On Jun 12, 2018, at 12:41 PM, Ken Mankoff <mankoff@gmail.com> wrote:
>> >
>> > Hi Chuck,
>> >
>> > It looks fine to me. I see:
>> >
>> > Name: fig:foo
>> > Lang: python
>> > Properties:
>> >       :header-args    :eval never-export
>> >       :header-args:python     nil
>> > Header Arguments:
>> >       :cache          no
>> >       :eval           never-export
>> >       :exports        results
>> >       :hlines         no
>> >       :noweb          yes
>> >       :results        file replace
>> >       :session        discharge_ts
>> >       :tangle         no
>> >
>> >
>>
>> And still the src blocks execute?
>>
>>
> No. The source blocks never execute. It just takes an entire minute to
> export the file with 200 source blocks. If they executed it would probably
> take a few hours.
>
>    -k.
>