Unable to download e-book cover

[Comfy.n]

Originally Posted by Hazily2513

Hello, I haven't been able to download covers using Google Images for over two weeks. I even tried the new, portable version of Caliber - also using VPN from different parts of the world.
Could you please help me?

Do you notice that if you try twice, three times, on the same title, eventually the cover gets downloaded?

By setting "Google Images" as the only metadata source, and clicking "Download only covers", I've noticed the same thing happen with various titles: first try, nothing. second time, nothing. third time, cover is found and downloaded! Sometimes just a second attempt is enough.

At first I thought this could be something related to Calibre user agents randomising, however from looking at the logs, I'd guess that's something else:

Spoiler:

#################### Log for Fables ####################

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36')]
Failed to download valid cover
Took 1.547957181930542 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
No images found for, title: 'Fables' and authors: ['Aesop']

************************************************** ******************************

#################### Log for Fables ####################

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36')]
Downloaded cover: 759x1000
Took 2.1541898250579834 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
Downloading 1 covers
Downloaded cover from: https://m.media-amazon.com/images/I/...1000_QL80_.jpg

************************************************** ******************************
---------------------------------------------------------------------
#################### Log for The Young Visiters: Or, Mr. Salteena’s Plan ####################

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36')]
Failed to download valid cover
Took 1.9357340335845947 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
No images found for, title: 'Young Visiters: Or, Mr. Salteena’s Plan' and authors: ['Daisy Ashford']

************************************************** ******************************

#################### Log for The Young Visiters: Or, Mr. Salteena’s Plan ####################

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36')]
Downloaded cover: 647x1000
Took 2.245108127593994 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
Downloading 1 covers
Downloaded cover from: https://m.media-amazon.com/images/I/...1000_QL80_.jpg

Same user agent, one attempt failed, the other succeeded. Two different titles in the above logs. And below are two attempts with different UAs and same title:

Spoiler:

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.2 Safari/605.1.15')]
Downloaded cover: 695x1000
Took 3.3367817401885986 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
Downloading 1 covers
Downloaded cover from: https://images.ucpress.edu/covers/is...0520267190.jpg

************************************************** ******************************


#################### Log for The Autobiography of Mark Twain ####################

****************************** Google Images Covers ******************************
Request extra headers: [('User-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36')]
Failed to download valid cover
Took 1.6460497379302979 seconds
Search URL: https://www.google.com/search?as_st=...=iar:t,ift:jpg
No images found for, title: 'Autobiography of Mark Twain' and authors: ['Mark Twain']

************************************************** ******************************

[kovidgoyal]

Intermittent issues where results are not found, are most likely because google is A/B testing a new website layout. Once it stabilizes the plugin can be updated.