I don't know how I've managed this, but my PC's #Nix installation is no longer able to do network operations and always fails with a cURL error "Failed to open/read local data from file/application". Heavily regretting my choice to prioritise a clean systemd-boot screen over having older generations I could restore to.

Edit: passing `-vvvvv` to Nix revealed this was actually a cURL regression that was being misreported by Nix github.com/curl/curl/issues/15