"Your extension was disabled because it is corrupted" — but no extension files are modified

lastorset

lastorset

For months now Quick Find for Opera has not been working: When I activate it (Ctrl+Shift+F), Opera for Linux says "Your extension was disabled because it is corrupted. Go to the extensions manager to repair it." Clicking "Repair" and trying to use it gave the exact same result.

This has happened on three separate computers. I am running Ubuntu GNOME, versions 16.10 and 17.04

For the longest time I thought this was a bug in the extension that I was too lazy to fix. Then it happened on another newly-installed extension: Easy Tab Manager and I got suspicious.

As recommended by kszularz in Your extension was disabled because it is corrupted. Go to the extensions manager and repair it., I ran

inotifywait -r -m -e \
        move -e create -e delete -e close_write -e modify \
        /home/lastorset/.config/opera/Extensions |
    while read path ev file; do
        echo $path$file $ev;
    done

but found that the last modification to happen was the hash computation:

[directory deletion and creation snipped]
./alfmlcakakiobbadicdfojldmmanlecg/0.0.12_0/_metadata CREATE,ISDIR
./alfmlcakakiobbadicdfojldmmanlecg/0.0.12_0/_metadata/verified_contents.json CLOSE_WRITE,CLOSE
./alfmlcakakiobbadicdfojldmmanlecg/0.0.12_0/_metadata/computed_hashes.json CREATE
./alfmlcakakiobbadicdfojldmmanlecg/0.0.12_0/_metadata/computed_hashes.json MODIFY
./alfmlcakakiobbadicdfojldmmanlecg/0.0.12_0/_metadata/computed_hashes.json CLOSE_WRITE,CLOSE

Nothing happens when I activate the extension and it is reported as corrupted. So the hashes should still match. Of course, it's possible I have some rootkit or malware installed on all three machines, but I am leaning toward there being a bug in the verification algorithm. Can anyone on the Desktop team comment?