I observe that /nix/store btrfs compression property gets inherited for locally built store paths as opposed to substituted from binary cache ones.
As evidence, grub2 2.02 wasn’t able to boot NixOS after I added an out-of-tree (locally built) kernel module to boot.extraModulePackages because of unsupported zstd compression of init and initrd files. grub2 2.04 successfully reads zstd compressed files.
1 Like