env
nano ~/.bashrc
export ELECTRON_MIRROR="https://mirrors.huaweicloud.com/electron/"
export ELECTRON_BUILDER_BINARIES_MIRROR="https://mirrors.huaweicloud.com/electron-builder-binaries/"
error:
dial tcp: lookup mirrors.huaweicloud.com on 192.168.0.1:53: lame referral
manual download
appimage cache file location is
~/.cache/electron-builder/appimage/appimage-12.0.1
appimage-12.0.1 is appimage-12.0.1.7z unzip result
directory like this

app-builder source code
/pkg/download/artifactDownloader.go
line:83 GetCacheDirectoryForArtifact(dirName)
line:91 CheckCache