Error: systemimage: Error: Error: wiping cache failed: Error: {"error":{"ki [...] '/cache/recovery': Directory not empty\nrm: can't remove '/cache/system': Device or resource busy"}

[KMK0815]

UBports Installer 0.5.6-beta (snap)
Environment: Ubuntu Core 20 linux 4.15.0-122-generic x64 with Node.js v12.16.3
Device: kagura
Target OS: Ubuntu Touch
Settings: undefined
OPEN-CUTS run: https://ubports.open-cuts.org/run/5f9acaa39702a600079d9e13
Log: N/A

Error:

Error: systemimage: Error: Error: wiping cache failed: Error: {"error":{"killed":false,"code":1,"signal":null,"cmd":"\"/snap/ubports-installer/305/app/resources/app.asar.unpacked/node_modules/android-tools-bin/dist/linux/x86/adb\" -P 5037 shell rm -rf /cache/*"},"stdout":"","stderr":"rm: can't remove '/cache/recovery/SWAP.img': Operation not permitted\nrm: can't remove '/cache/recovery': Directory not empty\nrm: can't remove '/cache/system': Device or resource busy"}