ghcup fails: remote yaml header unavailable

🍀[~] ghcup upgrade
[ Info  ] Upgrading GHCup...
[ Info  ] downloading: https://downloads.haskell.org/~ghcup/0.1.12/x86_64-linux-ghcup-0.1.12
[ Info  ] verifying digest of: ghcup
[ Info  ] Successfully upgraded GHCup to version 0.1.12

🍀[~] ghcup --version
The GHCup Haskell installer, version v0.1.12

🍀 [~]$ ghcup --verbose set ghc 8.6.5
[ Debug ] Identified Platform as: PlatformResult {_platform = Linux Alpine, _distroVersion = Just (Ideal (SemVer {_svMajor = 3, _svMinor = 12, _svPatch = 1, _svPreRel = [], _svMeta = []}))}
[ Debug ] Unable to get/parse Last-Modified header
[ Debug ] downloading: https://www.haskell.org/ghcup/data/ghcup-0.0.4.yaml
[ Warn  ] Could not get download info, trying cached version (this may not be recent!)
[ Error ] Error fetching download info: FileDoesNotExistError "/home/user/.ghcup/cache/ghcup-0.0.4.yaml"