arduino-cli config add board_manager.additional_urls https://raw.githubusercontent.com/esp8266/Arduino/refs/heads/master/package/package_esp8266com_index.template.json
arduino-cli core update-index
arduino-cli core install esp8266:esp8266

arduino-cli core install esp8266:esp8266
Downloading index: library_index.tar.bz2 downloaded
Downloading index: package_index.tar.bz2 downloaded
Downloading index: package_esp8266com_index.template.json downloaded
Downloading missing tool builtin:ctags@5.8-arduino11...
builtin:ctags@5.8-arduino11 downloaded
Installing builtin:ctags@5.8-arduino11...
Skipping tool configuration....
builtin:ctags@5.8-arduino11 installed
Downloading missing tool builtin:dfu-discovery@0.1.2...
builtin:dfu-discovery@0.1.2 downloaded
Installing builtin:dfu-discovery@0.1.2...
Skipping tool configuration....
builtin:dfu-discovery@0.1.2 installed
Downloading missing tool builtin:mdns-discovery@1.0.9...
builtin:mdns-discovery@1.0.9 downloaded
Installing builtin:mdns-discovery@1.0.9...
Skipping tool configuration....
builtin:mdns-discovery@1.0.9 installed
Downloading missing tool builtin:serial-discovery@1.4.1...
builtin:serial-discovery@1.4.1 downloaded
Installing builtin:serial-discovery@1.4.1...
Skipping tool configuration....
builtin:serial-discovery@1.4.1 installed
Downloading missing tool builtin:serial-monitor@0.15.0...
builtin:serial-monitor@0.15.0 downloaded
Installing builtin:serial-monitor@0.15.0...
Skipping tool configuration....
builtin:serial-monitor@0.15.0 installed
Downloading packages...
esp8266:xtensa-lx106-elf-gcc@3.2.0-gcc10.3-c791b74 downloaded
esp8266:mkspiffs@3.2.0-gcc10.3-c791b74 downloaded
esp8266:mklittlefs@3.2.0-gcc10.3-c791b74 downloaded
esp8266:python3@3.7.2-post2 downloaded
Error during install: removing corrupted archive file: remove /root/.arduino15/staging/packages: directory not empty