Ubuntu20.04 update出错：GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures were invalid: EXPKEYSIG 23E7166788B63E1E Yarn Packaging <yarn@dan.cx>
sudo apt-get update时出现以下错误：
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures were invalid: EXPKEYSIG 23E7166788B63E1E Yarn Packaging <yarn@dan.cx>
W: Failed to fetch https://dl.yarnpkg.com/debian/dists/stable/InRelease The following signatures were invalid: EXPKEYSIG 23E7166788B63E1E Yarn Packaging <yarn@dan.cx>
W: Some index files failed to download. They have been ignored, or old ones used instead.第一个解决方案无效：
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -askubuntu解决方案有效果：
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmor | sudo tee /usr/share/keyrings/yarnkey.gpg >/dev/null