Progress dialog stuck at "Verified X/X matches"

[glubsy]

Description of the bug
Sometimes there is a deadlock(?) after the message "Verified X/X matches".
I still cannot reliably reproduce the bug, and I don't really understand why it's happening exactly. Although it seems to happen
more reliably when attaching a debugger.

The log mentions "Creating X chunks with a chunk size of...", but the next expected log line "Found X matches" is not recorded.
The debugpy debugger (used in VS Code) shows sub-processes left hanging around.

After forcing the debug session to abort, a bunch of run.py seem to get orphaned and require a SIGKILL to terminate (technically not zombies, but similar). These must be remnants of the C binaries which have not returned properly to their run.py parent.

• This seems to happen only with the PE scanner
• Perhaps only occurs with scans done on smaller sets of files?

To Reproduce
Steps to reproduce the behavior:

1. Start a PE scanner with "Contents" scan option (fuzzyblock)
2. Reach the "Verified X/X matches" step in the progess bar
3. Process is stuck, main thread still running fine so the dialog can be canceled
4. Subsequent scans return the error "A previous action is still hanging in there. You can't start a new one yet. Wait a few seconds, then try again"
5. Exiting the application leaves a bunch or "run.py" processes (probably waiting for child processes to return)

Desktop:

• OS: Arch Linux
• Version 4.0.4 and latest git master branch