SUMMARY After updating to Calamares 3.2.30, Calamares no longer functions unless you have 2 or more CPU cores. It gets stuck on 'Checking module requirements...' when using the '-d' flag. STEPS TO REPRODUCE 1. Make an ISO with the latest version of Calamares, of Neon's compiling, in it 2. Boot into the ISO using a VM (or potentially machine too) with just one CPU core 3. Launch Calamares OBSERVED RESULT Calamares gets stuck. Using '-d' shows that it's stuck on that aforementioned line. EXPECTED RESULT Calamares functioning just fine SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: KDE neon User Edition 5.19.5 (in the screenshot shown below it's Feren OS on 20.04 using KDE neon User Edition 5.19.5's packages) (available in About System) KDE Plasma Version: 5.19.5 KDE Frameworks Version: 5.74.0 Qt Version: 5.15.0 ADDITIONAL INFORMATION ArcoLinux has also been encountering this exact same issue. Also when I compiled Calamares manually myself ahead of Neon compiling this version of Calamares (I compiled 3.2.30 beforehand) this issue didn't occur.
Screenshot of Feren OS using KDE neon User Edition 5.19.5's packages, including its Calamares package, with this said issue occurring: https://imgur.com/a/OJcpvS8
This was fixed in Calamares after 3.2.30, and the fix is in Calamares 3.2.31 (released in about an hour).