Error downloading PDF with python3

Frappe Framework Bug
1

I’ve just used bench migrate-env python3 to upgrade my python version but now I cannot download PDF files. It shows an internal server error with the following error in the logs

[2019-04-07 01:03:42 +0300] [19874] [ERROR] Error handling request /api/method/frappe.utils.print_format.download_pdf?doctype=Sales%20Invoice&name=%CE%99%CE%9F-%CE%A4%CE%A0%CE%A5-00048&format=Invoice%20-%20Greek%20ORIGINAL&no_letterhead=1&_lang=en
Traceback (most recent call last):
  File "/home/frappe/frappe-bench/env/lib/python3.5/site-packages/gunicorn/workers/sync.py", line 135, in handle
    self.handle_request(listener, req, client, addr)
  File "/home/frappe/frappe-bench/env/lib/python3.5/site-packages/gunicorn/workers/sync.py", line 182, in handle_request
    resp.write(item)
  File "/home/frappe/frappe-bench/env/lib/python3.5/site-packages/gunicorn/http/wsgi.py", line 333, in write
    self.send_headers()
  File "/home/frappe/frappe-bench/env/lib/python3.5/site-packages/gunicorn/http/wsgi.py", line 329, in send_headers
    util.write(self.sock, util.to_bytestring(header_str, "ascii"))
  File "/home/frappe/frappe-bench/env/lib/python3.5/site-packages/gunicorn/util.py", line 507, in to_bytestring
    return value.encode(encoding)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 160-163: ordinal not in range(128)

Any ideas how to fix?

2

Can you say what version bench and ERPNext, and also the output of: locale from a terminal? Is there a non standard character in the form ? Perhaps post a screenshot of the form before trying to convert to PDF.

Just a couple things that might help us help…Preformatted text

3

Hi of course I can provide any info needed.

bench: 4.1.0
ERPNext: v12.x.x-develop () (develop)
Frappe Framework: v12.x.x-develop () (develop)

Here’s the form

image
image1146×802 22.5 KB

And as soon as I press on PDF the error appears due to
frappe-bench/env/lib/python3.5/site-packages/gunicorn/http/wsgi.py:329

which forces ascii conversion.
util.write(self.sock, util.to_bytestring(header_str, "ascii"))

If I hardcode utf8 here it works but pretty much any form containing anything other than english breaks. Even standard forms.

Output of locale
LANG=en_US.UTF-8
LANGUAGE=en_US:
LC_CTYPE=“en_US.UTF-8”
LC_NUMERIC=“en_US.UTF-8”
LC_TIME=“en_US.UTF-8”
LC_COLLATE=“en_US.UTF-8”
LC_MONETARY=“en_US.UTF-8”
LC_MESSAGES=“en_US.UTF-8”
LC_PAPER=“en_US.UTF-8”
LC_NAME=“en_US.UTF-8”
LC_ADDRESS=“en_US.UTF-8”
LC_TELEPHONE=“en_US.UTF-8”
LC_MEASUREMENT=“en_US.UTF-8”
LC_IDENTIFICATION=“en_US.UTF-8”
LC_ALL=

4

If gunicorn is suspect, I wonder if installing python3-gunicorn would help. Otherwise , a google search of relevant parts of the UnicodeEncodeError message + ERPNext turns up a few posts that might help. .

5

Thanks for trying to help. Unfortunately installing python3-gunicorn made no difference as the code is still there converting utf8 characters to ascii.
I think this will need a lot more info from the devs to troubleshoot.

6

While waiting for devs or others to notice, perhaps try a couple things to see if the cause can be narrowed.

If Letter Head is unchecked , and/or if Settings, Print without letterhead - does it change anything?

If a new form is created, without any vestiges of the old ones, can it be printed as PDF?

7

“pretty much any form containing anything other than english breaks. Even standard forms.”

Please report this on Issues · frappe/erpnext · GitHub and link here.

For example this notes gotchas best resolved IMHO with a test environment to identify the correct fix

8

I’ve opened an issue regarding this problem with python3 and unicode characters in PDF · Issue #17536 · frappe/erpnext · GitHub.